CVE-2026-19668
MEDIUM 5.3A BIND recursive resolver may experience excessive resource consumption if it encounters large numbers of a particular kind of invalid DNSSEC record. Default limits on "max-records-per-type" and "max-types-per-name" help mitigate the exposure. This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1.
No known exploitation, public exploit, or elevated probability at this time. Track for changes.
Exploitation likelihood
0.5%chance of exploitation in 30 days · 41st percentile
Impact if exploited
5.3CVSS 3.1 · MEDIUM
- ConfidentialityNone
- IntegrityNone
- AvailabilityLow
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ✓Privileges: No account or privileges required
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept
No public PoC is currently catalogued.
Search for new PoCs
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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:
Weakness (CWE)
- CWE-407: Inefficient Algorithmic Complexity
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
References and research data (JSON)
Vendor product assessments
Showing 32 of 102 vendor product statements; 70 omitted. Read the full vendor advisory.
bind-0:9.20.29-0.1.hum1@aarch64 as a component of Red Hat Hardened Images · fixed
Vendor assessment for this product only.
pkg:rpm/redhat/[email protected]?arch=aarch64&distro=hummingbird-20251124&repository_id=public-hummingbird-aarch64-rpms
- vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/ Vendor guidance
- workaround: To mitigate potential denial of service, ensure that the BIND recursive resolver's configuration includes appropriate limits for `max-records-per-type` and `max-types-per-name` within the `named.conf` file. These settings help control resource consumption when encountering invalid DNSSEC records. A restart of the `named` service is required for any configuration changes to take effect.
bind-0:9.20.29-0.1.hum1@src as a component of Red Hat Hardened Images · fixed
Vendor assessment for this product only.
pkg:rpm/redhat/[email protected]?arch=src&distro=hummingbird-20251124&repository_id=public-hummingbird-source-rpms
- vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/ Vendor guidance
- workaround: To mitigate potential denial of service, ensure that the BIND recursive resolver's configuration includes appropriate limits for `max-records-per-type` and `max-types-per-name` within the `named.conf` file. These settings help control resource consumption when encountering invalid DNSSEC records. A restart of the `named` service is required for any configuration changes to take effect.
bind-chroot-0:9.20.29-0.1.hum1@aarch64 as a component of Red Hat Hardened Images · fixed
Vendor assessment for this product only.
pkg:rpm/redhat/[email protected]?arch=aarch64&distro=hummingbird-20251124&repository_id=public-hummingbird-aarch64-rpms
- vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/ Vendor guidance
- workaround: To mitigate potential denial of service, ensure that the BIND recursive resolver's configuration includes appropriate limits for `max-records-per-type` and `max-types-per-name` within the `named.conf` file. These settings help control resource consumption when encountering invalid DNSSEC records. A restart of the `named` service is required for any configuration changes to take effect.
bind-chroot-0:9.20.29-0.1.hum1@x86_64 as a component of Red Hat Hardened Images · fixed
Vendor assessment for this product only.
pkg:rpm/redhat/[email protected]?arch=x86_64&distro=hummingbird-20251124&repository_id=public-hummingbird-x86_64-rpms
- vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/ Vendor guidance
- workaround: To mitigate potential denial of service, ensure that the BIND recursive resolver's configuration includes appropriate limits for `max-records-per-type` and `max-types-per-name` within the `named.conf` file. These settings help control resource consumption when encountering invalid DNSSEC records. A restart of the `named` service is required for any configuration changes to take effect.
bind-devel-0:9.20.29-0.1.hum1@x86_64 as a component of Red Hat Hardened Images · fixed
Vendor assessment for this product only.
pkg:rpm/redhat/[email protected]?arch=x86_64&distro=hummingbird-20251124&repository_id=public-hummingbird-x86_64-rpms
- vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/ Vendor guidance
- workaround: To mitigate potential denial of service, ensure that the BIND recursive resolver's configuration includes appropriate limits for `max-records-per-type` and `max-types-per-name` within the `named.conf` file. These settings help control resource consumption when encountering invalid DNSSEC records. A restart of the `named` service is required for any configuration changes to take effect.
bind-dnssec-utils-0:9.20.29-0.1.hum1@aarch64 as a component of Red Hat Hardened Images · fixed
Vendor assessment for this product only.
pkg:rpm/redhat/[email protected]?arch=aarch64&distro=hummingbird-20251124&repository_id=public-hummingbird-aarch64-rpms
- vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/ Vendor guidance
- workaround: To mitigate potential denial of service, ensure that the BIND recursive resolver's configuration includes appropriate limits for `max-records-per-type` and `max-types-per-name` within the `named.conf` file. These settings help control resource consumption when encountering invalid DNSSEC records. A restart of the `named` service is required for any configuration changes to take effect.
bind-dnssec-utils-0:9.20.29-0.1.hum1@x86_64 as a component of Red Hat Hardened Images · fixed
Vendor assessment for this product only.
pkg:rpm/redhat/[email protected]?arch=x86_64&distro=hummingbird-20251124&repository_id=public-hummingbird-x86_64-rpms
- vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/ Vendor guidance
- workaround: To mitigate potential denial of service, ensure that the BIND recursive resolver's configuration includes appropriate limits for `max-records-per-type` and `max-types-per-name` within the `named.conf` file. These settings help control resource consumption when encountering invalid DNSSEC records. A restart of the `named` service is required for any configuration changes to take effect.
bind-doc-0:9.20.29-0.1.hum1@noarch@public-hummingbird-x86_64-rpms as a component of Red Hat Hardened Images · fixed
Vendor assessment for this product only.
pkg:rpm/redhat/[email protected]?arch=noarch&distro=hummingbird-20251124&repository_id=public-hummingbird-x86_64-rpms
- vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/ Vendor guidance
- workaround: To mitigate potential denial of service, ensure that the BIND recursive resolver's configuration includes appropriate limits for `max-records-per-type` and `max-types-per-name` within the `named.conf` file. These settings help control resource consumption when encountering invalid DNSSEC records. A restart of the `named` service is required for any configuration changes to take effect.
bind-libs-0:9.20.29-0.1.hum1@aarch64 as a component of Red Hat Hardened Images · fixed
Vendor assessment for this product only.
pkg:rpm/redhat/[email protected]?arch=aarch64&distro=hummingbird-20251124&repository_id=public-hummingbird-aarch64-rpms
- vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/ Vendor guidance
- workaround: To mitigate potential denial of service, ensure that the BIND recursive resolver's configuration includes appropriate limits for `max-records-per-type` and `max-types-per-name` within the `named.conf` file. These settings help control resource consumption when encountering invalid DNSSEC records. A restart of the `named` service is required for any configuration changes to take effect.
bind-utils-0:9.20.29-0.1.hum1@aarch64 as a component of Red Hat Hardened Images · fixed
Vendor assessment for this product only.
pkg:rpm/redhat/[email protected]?arch=aarch64&distro=hummingbird-20251124&repository_id=public-hummingbird-aarch64-rpms
- vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/ Vendor guidance
- workaround: To mitigate potential denial of service, ensure that the BIND recursive resolver's configuration includes appropriate limits for `max-records-per-type` and `max-types-per-name` within the `named.conf` file. These settings help control resource consumption when encountering invalid DNSSEC records. A restart of the `named` service is required for any configuration changes to take effect.
bind-utils-0:9.20.29-0.1.hum1@x86_64 as a component of Red Hat Hardened Images · fixed
Vendor assessment for this product only.
pkg:rpm/redhat/[email protected]?arch=x86_64&distro=hummingbird-20251124&repository_id=public-hummingbird-x86_64-rpms
- vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/ Vendor guidance
- workaround: To mitigate potential denial of service, ensure that the BIND recursive resolver's configuration includes appropriate limits for `max-records-per-type` and `max-types-per-name` within the `named.conf` file. These settings help control resource consumption when encountering invalid DNSSEC records. A restart of the `named` service is required for any configuration changes to take effect.
bind as a component of Red Hat Enterprise Linux 10 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/bind
- workaround: To mitigate potential denial of service, ensure that the BIND recursive resolver's configuration includes appropriate limits for `max-records-per-type` and `max-types-per-name` within the `named.conf` file. These settings help control resource consumption when encountering invalid DNSSEC records. A restart of the `named` service is required for any configuration changes to take effect.
- none available: Fix deferred
bind-utils as a component of Red Hat Enterprise Linux 10 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/bind-utils
- workaround: To mitigate potential denial of service, ensure that the BIND recursive resolver's configuration includes appropriate limits for `max-records-per-type` and `max-types-per-name` within the `named.conf` file. These settings help control resource consumption when encountering invalid DNSSEC records. A restart of the `named` service is required for any configuration changes to take effect.
- none available: Fix deferred
bind-libs-lite as a component of Red Hat Enterprise Linux 7 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/bind-libs-lite
- workaround: To mitigate potential denial of service, ensure that the BIND recursive resolver's configuration includes appropriate limits for `max-records-per-type` and `max-types-per-name` within the `named.conf` file. These settings help control resource consumption when encountering invalid DNSSEC records. A restart of the `named` service is required for any configuration changes to take effect.
- none available: Fix deferred
bind-sdb as a component of Red Hat Enterprise Linux 7 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/bind-sdb
- workaround: To mitigate potential denial of service, ensure that the BIND recursive resolver's configuration includes appropriate limits for `max-records-per-type` and `max-types-per-name` within the `named.conf` file. These settings help control resource consumption when encountering invalid DNSSEC records. A restart of the `named` service is required for any configuration changes to take effect.
- none available: Fix deferred
bind-export-libs as a component of Red Hat Enterprise Linux 8 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/bind-export-libs
- workaround: To mitigate potential denial of service, ensure that the BIND recursive resolver's configuration includes appropriate limits for `max-records-per-type` and `max-types-per-name` within the `named.conf` file. These settings help control resource consumption when encountering invalid DNSSEC records. A restart of the `named` service is required for any configuration changes to take effect.
- none available: Fix deferred
bind-pkcs11-libs as a component of Red Hat Enterprise Linux 8 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/bind-pkcs11-libs
- workaround: To mitigate potential denial of service, ensure that the BIND recursive resolver's configuration includes appropriate limits for `max-records-per-type` and `max-types-per-name` within the `named.conf` file. These settings help control resource consumption when encountering invalid DNSSEC records. A restart of the `named` service is required for any configuration changes to take effect.
- none available: Fix deferred
bind9.16-chroot as a component of Red Hat Enterprise Linux 8 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/bind9.16-chroot
- workaround: To mitigate potential denial of service, ensure that the BIND recursive resolver's configuration includes appropriate limits for `max-records-per-type` and `max-types-per-name` within the `named.conf` file. These settings help control resource consumption when encountering invalid DNSSEC records. A restart of the `named` service is required for any configuration changes to take effect.
- none available: Fix deferred
python3-bind as a component of Red Hat Enterprise Linux 8 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/python3-bind
- workaround: To mitigate potential denial of service, ensure that the BIND recursive resolver's configuration includes appropriate limits for `max-records-per-type` and `max-types-per-name` within the `named.conf` file. These settings help control resource consumption when encountering invalid DNSSEC records. A restart of the `named` service is required for any configuration changes to take effect.
- none available: Fix deferred
bind-doc as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/bind-doc
- workaround: To mitigate potential denial of service, ensure that the BIND recursive resolver's configuration includes appropriate limits for `max-records-per-type` and `max-types-per-name` within the `named.conf` file. These settings help control resource consumption when encountering invalid DNSSEC records. A restart of the `named` service is required for any configuration changes to take effect.
- none available: Fix deferred
bind9.18-dnssec-utils as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/bind9.18-dnssec-utils
- workaround: To mitigate potential denial of service, ensure that the BIND recursive resolver's configuration includes appropriate limits for `max-records-per-type` and `max-types-per-name` within the `named.conf` file. These settings help control resource consumption when encountering invalid DNSSEC records. A restart of the `named` service is required for any configuration changes to take effect.
- none available: Fix deferred
openshift/ose-rhel-coreos-9 as a component of Red Hat OpenShift Container Platform 4 · known affected
Vendor assessment for this product only.
pkg:oci/[email protected]?repository_url=registry.redhat.io/openshift/ose-rhel-coreos-9
- workaround: To mitigate potential denial of service, ensure that the BIND recursive resolver's configuration includes appropriate limits for `max-records-per-type` and `max-types-per-name` within the `named.conf` file. These settings help control resource consumption when encountering invalid DNSSEC records. A restart of the `named` service is required for any configuration changes to take effect.
- none available: Fix deferred
bind as a component of Red Hat Enterprise Linux 6 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/bind
Red Hat · CVE-2026-19668 · Updated 2026-09-21T11:37:41+00:00bind-chroot as a component of Red Hat Enterprise Linux 6 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/bind-chroot
Red Hat · CVE-2026-19668 · Updated 2026-09-21T11:37:41+00:00bind-devel as a component of Red Hat Enterprise Linux 6 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/bind-devel
Red Hat · CVE-2026-19668 · Updated 2026-09-21T11:37:41+00:00bind-sdb as a component of Red Hat Enterprise Linux 6 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/bind-sdb
Red Hat · CVE-2026-19668 · Updated 2026-09-21T11:37:41+00:00bind-utils as a component of Red Hat Enterprise Linux 6 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/bind-utils
Red Hat · CVE-2026-19668 · Updated 2026-09-21T11:37:41+00:00bind.src as a component of Red Hat Enterprise Linux 6 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/bind?arch=src
Red Hat · CVE-2026-19668 · Updated 2026-09-21T11:37:41+00:00dhcp-client as a component of Red Hat Enterprise Linux 9 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/dhcp-client
Red Hat · CVE-2026-19668 · Updated 2026-09-21T11:37:41+00:00dhcp-relay as a component of Red Hat Enterprise Linux 9 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/dhcp-relay
Red Hat · CVE-2026-19668 · Updated 2026-09-21T11:37:41+00:00dhcp-server as a component of Red Hat Enterprise Linux 9 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/dhcp-server
Red Hat · CVE-2026-19668 · Updated 2026-09-21T11:37:41+00:00dhcp.src as a component of Red Hat Enterprise Linux 9 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/dhcp?arch=src
Red Hat · CVE-2026-19668 · Updated 2026-09-21T11:37:41+00:00
All CVSS metrics
- MEDIUM 5.3 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - MEDIUM 5.3 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
References
Patches & mitigations
- https://downloads.isc.org/isc/bind9/9.20.29 CVE record · isc · Updated 2026-09-16T14:12:34.380Z
NVD · CVE-2026-19668 · Updated 2026-09-17T19:16:42.057
Red Hat · CVE-2026-19668 · Updated 2026-09-21T11:37:41+00:00 - https://downloads.isc.org/isc/bind9/9.21.26 CVE record · isc · Updated 2026-09-16T14:12:34.380Z
NVD · CVE-2026-19668 · Updated 2026-09-17T19:16:42.057
Red Hat · CVE-2026-19668 · Updated 2026-09-21T11:37:41+00:00
Advisories
- https://kb.isc.org/docs/cve-2026-19668 CVE record · isc · Updated 2026-09-16T14:12:34.380Z
NVD · CVE-2026-19668 · Updated 2026-09-17T19:16:42.057
Red Hat · CVE-2026-19668 · Updated 2026-09-21T11:37:41+00:00 - https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-19668.json Red Hat · CVE-2026-19668 · Updated 2026-09-21T11:37:41+00:00
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-80783 EUVD · EUVD-2026-80783
Technical & other
- https://access.redhat.com/security/cve/CVE-2026-19668 Red Hat · CVE-2026-19668 · Updated 2026-09-21T11:37:41+00:00
- https://bugzilla.redhat.com/show_bug.cgi?id=2535476 Red Hat · CVE-2026-19668 · Updated 2026-09-21T11:37:41+00:00
- https://www.cve.org/CVERecord?id=CVE-2026-19668 Red Hat · CVE-2026-19668 · Updated 2026-09-21T11:37:41+00:00
- https://nvd.nist.gov/vuln/detail/CVE-2026-19668 Red Hat · CVE-2026-19668 · Updated 2026-09-21T11:37:41+00:00
- https://access.redhat.com/errata/RHSA-2026:68279 Red Hat · CVE-2026-19668 · Updated 2026-09-21T11:37:41+00:00