CVE-2026-98173
HIGH 7.5In the Linux kernel, the following vulnerability has been resolved: smb: client: fix use-after-free of iface in cifs_try_adding_channels() cifs_try_adding_channels() iterates ses->iface_list with list_for_each_entry_safe_from(), which captures the next entry (niface) under iface_lock. The loop body then drops iface_lock for the whole duration of cifs_ses_add_channel(). A concurrent interface refresh (SMB3_request_interfaces() -> parse_server_interfaces()) marks all ifaces inactive and removes and frees any that are not re-advertised via list_del() + kref_put(), where release_iface() is a bare kfree(). Since niface typically has no channel holding a reference, the list reference is its last and it can be freed inside the unlocked window. On continue, the iterator advance step then dereferences niface->iface_head.next, and the loop body reads iface->rdma_capable/is_active, both on freed memory. Fix this by never keeping an unreferenced list pointer across the unlocked window. Each channel attempt now re-scans the list from the head under iface_lock, takes a kref on the selected candidate, and passes only that referenced candidate to cifs_ses_add_channel(). weight_fulfilled still tracks selection progress, so restarting the scan preserves the original weighted distribution and the weight_fulfilled-before-kref_put ordering on the failure path. Add a per-pass attempts cap so a flapping interface refresh cannot keep the inner loop spinning within a single tries increment.
Severe if exploited (CVSS 7.5), but no known exploitation and low modeled probability. Patch on a normal cadence.
Exploitation likelihood
0.3%chance of exploitation in 30 days · 25th percentile
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:
Weakness (CWE)
Not classified.
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 277 vendor product statements; 245 omitted. Read the full vendor advisory.
kernel as a component of Red Hat Enterprise Linux 10 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel
- none available: Affected
kernel-core as a component of Red Hat Enterprise Linux 10 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-core
- none available: Affected
kernel-modules-extra-matched as a component of Red Hat Enterprise Linux 10 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-modules-extra-matched
- none available: Affected
kernel-rt-debug as a component of Red Hat Enterprise Linux 10 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-rt-debug
- none available: Affected
kernel-uki-virt as a component of Red Hat Enterprise Linux 10 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-uki-virt
- none available: Affected
kernel as a component of Red Hat Enterprise Linux 8 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel
- none available: Affected
kernel-modules as a component of Red Hat Enterprise Linux 8 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-modules
- none available: Affected
kernel-rt-modules-internal as a component of Red Hat Enterprise Linux 8 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-rt-modules-internal
- none available: Affected
python3-perf as a component of Red Hat Enterprise Linux 8 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/python3-perf
- none available: Affected
kernel-64k-modules as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-64k-modules
- none available: Affected
kernel-debug-modules-internal as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-debug-modules-internal
- none available: Affected
kernel-rt-64k-core as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-rt-64k-core
- none available: Affected
kernel-rt-64k-modules-core as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-rt-64k-modules-core
- none available: Affected
kernel-rt-devel-matched as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-rt-devel-matched
- none available: Affected
kernel-zfcpdump as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-zfcpdump
- none available: Affected
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/ose-rhel-coreos-9?repository_url=registry.redhat.io/openshift/ose-rhel-coreos-9
- none available: Affected
kernel 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/kernel
Red Hat · CVE-2026-98173 · Updated 2026-10-08T08:52:13+00:00kernel-debug 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/kernel-debug
Red Hat · CVE-2026-98173 · Updated 2026-10-08T08:52:13+00:00kernel-doc 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/kernel-doc
Red Hat · CVE-2026-98173 · Updated 2026-10-08T08:52:13+00:00kernel-headers 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/kernel-headers
Red Hat · CVE-2026-98173 · Updated 2026-10-08T08:52:13+00:00kernel.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/kernel?arch=src
Red Hat · CVE-2026-98173 · Updated 2026-10-08T08:52:13+00:00bpftool as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/bpftool
Red Hat · CVE-2026-98173 · Updated 2026-10-08T08:52:13+00:00kernel-bootwrapper as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-bootwrapper
Red Hat · CVE-2026-98173 · Updated 2026-10-08T08:52:13+00:00kernel-devel as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-devel
Red Hat · CVE-2026-98173 · Updated 2026-10-08T08:52:13+00:00kernel-headers as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-headers
Red Hat · CVE-2026-98173 · Updated 2026-10-08T08:52:13+00:00kernel-rt as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-rt
Red Hat · CVE-2026-98173 · Updated 2026-10-08T08:52:13+00:00kernel-rt-debug-kvm as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-rt-debug-kvm
Red Hat · CVE-2026-98173 · Updated 2026-10-08T08:52:13+00:00kernel-rt-kvm as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-rt-kvm
Red Hat · CVE-2026-98173 · Updated 2026-10-08T08:52:13+00:00kernel-rt-trace-kvm as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-rt-trace-kvm
Red Hat · CVE-2026-98173 · Updated 2026-10-08T08:52:13+00:00kernel-tools as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-tools
Red Hat · CVE-2026-98173 · Updated 2026-10-08T08:52:13+00:00kernel.src as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel?arch=src
Red Hat · CVE-2026-98173 · Updated 2026-10-08T08:52:13+00:00openshift/ose-rhel-coreos-8 as a component of Red Hat OpenShift Container Platform 4 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:oci/ose-rhel-coreos-8?repository_url=registry.redhat.io/openshift/ose-rhel-coreos-8
Red Hat · CVE-2026-98173 · Updated 2026-10-08T08:52:13+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
Advisories
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98173.json Red Hat · CVE-2026-98173 · Updated 2026-10-08T08:52:13+00:00
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-93101 EUVD · EUVD-2026-93101
Technical & other
- https://git.kernel.org/stable/c/ee0d8f83d68f6e6509f092c997ccab3c8c801538CVE record · Linux · Updated 2026-10-21T12:54:49.437Z
NVD · CVE-2026-98173 · Updated 2026-10-21T13:21:25.150 - https://git.kernel.org/stable/c/c941f1ebfd26f683de81091473f3596a218abff0CVE record · Linux · Updated 2026-10-21T12:54:49.437Z
NVD · CVE-2026-98173 · Updated 2026-10-21T13:21:25.150 - https://git.kernel.org/stable/c/e99040e5e9c60441e6b4725e1a7b88c3106ae903CVE record · Linux · Updated 2026-10-21T12:54:49.437Z
NVD · CVE-2026-98173 · Updated 2026-10-21T13:21:25.150 - https://git.kernel.org/stable/c/ec36b38e65596950e6c29bed7dfc90b98707c19cCVE record · Linux · Updated 2026-10-21T12:54:49.437Z
NVD · CVE-2026-98173 · Updated 2026-10-21T13:21:25.150 - https://git.kernel.org/stable/c/d034e836eefd7ce75e588f7031cffbeec594f5acCVE record · Linux · Updated 2026-10-21T12:54:49.437Z
NVD · CVE-2026-98173 · Updated 2026-10-21T13:21:25.150 - https://access.redhat.com/security/cve/CVE-2026-98173 Red Hat · CVE-2026-98173 · Updated 2026-10-08T08:52:13+00:00
- https://bugzilla.redhat.com/show_bug.cgi?id=2546481 Red Hat · CVE-2026-98173 · Updated 2026-10-08T08:52:13+00:00
- https://www.cve.org/CVERecord?id=CVE-2026-98173 Red Hat · CVE-2026-98173 · Updated 2026-10-08T08:52:13+00:00
- https://nvd.nist.gov/vuln/detail/CVE-2026-98173 Red Hat · CVE-2026-98173 · Updated 2026-10-08T08:52:13+00:00
- https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98173.mbox Red Hat · CVE-2026-98173 · Updated 2026-10-08T08:52:13+00:00