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CVE-2026-88806

HIGH 7.5

Published 2026-09-21 · Last modified 2026-09-22

A malicious X server could exploit a buffer overflow in libX11 before 1.8.14 during handling of XkbGetMap overflowing the key_sym_map.

ELEVATED IMPACT

Severe if exploited (CVSS 7.5), but no known exploitation and low modeled probability. Patch on a normal cadence.

Exploitation likelihood

0.2%chance of exploitation in 30 days · 10th percentile

○ In CISA KEV ○ Catalogued PoC

Impact if exploited

7.5CVSS 3.1 · HIGH

  • ConfidentialityHigh
  • IntegrityHigh
  • AvailabilityHigh

What an attacker needs

  • ✓Access: Reachable over the network — no local access needed
  • ✓Privileges: No account or privileges required
  • ⚠User interaction: A user must take an action (click / open a file)
  • ⚠Complexity: Needs a race window or specific setup

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept

No public PoC is currently catalogued.

Search for new PoCs

Search GitHub now — results may be empty or unverified.

Tracked sources are checked daily for recent CVEs, including PoCs published after the original disclosure. A later release appears after a tracked source lists it and a refresh succeeds.

Data snapshot:

Affected

Vendors X.Org

Products Libx11

Weakness (CWE)

  • CWE-122: Heap-based buffer overflow

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

References and research data (JSON)

Vendor product assessments

Showing 32 of 50 vendor product statements; 18 omitted. Read the full vendor advisory.

  • libX11-0:1.6.8-10.el8_10.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 8) · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]_10?arch=aarch64

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Vendor guidance
    • workaround: To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`.
    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00
  • libX11-0:1.6.8-10.el8_10.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 8) · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]_10?arch=ppc64le

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Vendor guidance
    • workaround: To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`.
    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00
  • libX11-0:1.6.8-10.el8_10.src as a component of Red Hat Enterprise Linux AppStream (v. 8) · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]_10?arch=src

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Vendor guidance
    • workaround: To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`.
    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00
  • libX11-common-0:1.6.8-10.el8_10.noarch as a component of Red Hat Enterprise Linux AppStream (v. 8) · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]_10?arch=noarch

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Vendor guidance
    • workaround: To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`.
    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00
  • libX11-debuginfo-0:1.6.8-10.el8_10.i686 as a component of Red Hat Enterprise Linux AppStream (v. 8) · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]_10?arch=i686

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Vendor guidance
    • workaround: To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`.
    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00
  • libX11-debuginfo-0:1.6.8-10.el8_10.s390x as a component of Red Hat Enterprise Linux AppStream (v. 8) · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]_10?arch=s390x

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Vendor guidance
    • workaround: To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`.
    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00
  • libX11-debugsource-0:1.6.8-10.el8_10.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 8) · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]_10?arch=aarch64

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Vendor guidance
    • workaround: To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`.
    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00
  • libX11-debugsource-0:1.6.8-10.el8_10.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 8) · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]_10?arch=ppc64le

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Vendor guidance
    • workaround: To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`.
    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00
  • libX11-devel-0:1.6.8-10.el8_10.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 8) · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]_10?arch=aarch64

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Vendor guidance
    • workaround: To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`.
    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00
  • libX11-devel-0:1.6.8-10.el8_10.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 8) · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]_10?arch=ppc64le

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Vendor guidance
    • workaround: To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`.
    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00
  • libX11-devel-0:1.6.8-10.el8_10.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 8) · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]_10?arch=x86_64

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Vendor guidance
    • workaround: To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`.
    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00
  • libX11-xcb-0:1.6.8-10.el8_10.i686 as a component of Red Hat Enterprise Linux AppStream (v. 8) · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]_10?arch=i686

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Vendor guidance
    • workaround: To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`.
    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00
  • libX11-xcb-0:1.6.8-10.el8_10.s390x as a component of Red Hat Enterprise Linux AppStream (v. 8) · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]_10?arch=s390x

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Vendor guidance
    • workaround: To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`.
    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00
  • libX11-xcb-debuginfo-0:1.6.8-10.el8_10.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 8) · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]_10?arch=aarch64

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Vendor guidance
    • workaround: To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`.
    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00
  • libX11-xcb-debuginfo-0:1.6.8-10.el8_10.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 8) · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]_10?arch=ppc64le

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Vendor guidance
    • workaround: To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`.
    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00
  • libX11-xcb-debuginfo-0:1.6.8-10.el8_10.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 8) · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]_10?arch=x86_64

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Vendor guidance
    • workaround: To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`.
    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00
  • libX11-common as a component of Red Hat Enterprise Linux 10 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/libX11-common

    • workaround: To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`.
    • none available: Affected
    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00
  • libX11-devel as a component of Red Hat Enterprise Linux 10 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/libX11-devel

    • workaround: To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`.
    • none available: Affected
    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00
  • libX11-xcb as a component of Red Hat Enterprise Linux 10 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/libX11-xcb

    • workaround: To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`.
    • none available: Affected
    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00
  • libX11.src as a component of Red Hat Enterprise Linux 10 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/libX11?arch=src

    • workaround: To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`.
    • none available: Affected
    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00
  • libX11-common as a component of Red Hat Enterprise Linux 6 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/libX11-common

    • workaround: To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`.
    • no fix planned: Out of support scope
    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00
  • libX11-devel as a component of Red Hat Enterprise Linux 6 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/libX11-devel

    • workaround: To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`.
    • no fix planned: Out of support scope
    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00
  • libX11.src as a component of Red Hat Enterprise Linux 6 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/libX11?arch=src

    • workaround: To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`.
    • no fix planned: Out of support scope
    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00
  • libX11 as a component of Red Hat Enterprise Linux 7 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/libX11

    • workaround: To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`.
    • none available: Affected
    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00
  • libX11-common as a component of Red Hat Enterprise Linux 7 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/libX11-common

    • workaround: To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`.
    • none available: Affected
    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00
  • libX11-devel as a component of Red Hat Enterprise Linux 7 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/libX11-devel

    • workaround: To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`.
    • none available: Affected
    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00
  • libX11.src as a component of Red Hat Enterprise Linux 7 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/libX11?arch=src

    • workaround: To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`.
    • none available: Affected
    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00
  • libX11-common as a component of Red Hat Enterprise Linux 9 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/libX11-common

    • workaround: To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`.
    • none available: Affected
    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00
  • libX11-devel as a component of Red Hat Enterprise Linux 9 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/libX11-devel

    • workaround: To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`.
    • none available: Affected
    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00
  • libX11-xcb as a component of Red Hat Enterprise Linux 9 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/libX11-xcb

    • workaround: To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`.
    • none available: Affected
    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00
  • libX11.src as a component of Red Hat Enterprise Linux 9 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/libX11?arch=src

    • workaround: To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`.
    • none available: Affected
    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00
  • libX11.src as a component of Red Hat Hardened Images · known not affected

    Vendor assessment for this product only.

    Reason: component not present

    pkg:rpm/redhat/libX11?arch=src

    Red Hat · CVE-2026-88806 · Updated 2026-10-26T01:43:42+00:00

All CVSS metrics

  • HIGH 7.5 v3.1 · CNA Primary
    CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
  • HIGH 7.5 v3.1 · NVD Secondary
    CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

References

Patches & mitigations

Advisories

Technical & other

Sources: NVD · CVE.org · EPSS