CVE-2026-98374
HIGH 8.8In the Linux kernel, the following vulnerability has been resolved: tcp: fix use-after-free of retransmit_skb_hint in tcp_send_synack() When tcp_send_synack() replaces the cloned SYN skb at the head of the retransmit queue with a copy, it frees the original with tcp_rtx_queue_unlink_and_free() and only repairs tp->highest_sack. tp->retransmit_skb_hint keeps pointing at the freed skbuff_fclone_cache object. The dangling hint is read in tcp_verify_retransmit_hint() and used as the root of the rbtree walk in tcp_xmit_retransmit_queue(). An unprivileged TFO client (sendmsg(MSG_FASTOPEN)) can arm the hint with an attacker-supplied ICMP fragmentation-needed message, after which a simultaneous open frees the armed SYN skb: BUG: KASAN: slab-use-after-free in tcp_mark_skb_lost (net/ipv4/tcp_input.c:1316) Read of size 4 at addr ffff88800604d928 by task swapper/1/0 Call Trace: tcp_mark_skb_lost (net/ipv4/tcp_input.c:1316) tcp_simple_retransmit (net/ipv4/tcp_input.c:3158) tcp_v4_err (net/ipv4/tcp_ipv4.c:587) Sync the hint to the copy.
Severe if exploited (CVSS 8.8), but no known exploitation and low modeled probability. Patch on a normal cadence.
Exploitation likelihood
0.3%chance of exploitation in 30 days · 22nd percentile
Impact if exploited
8.8CVSS 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: 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)
Not classified.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
References and research data (JSON)
Vendor product assessments
Showing 32 of 278 vendor product statements; 246 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-64k-modules-core as a component of Red Hat Enterprise Linux 10 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-64k-modules-core
- none available: Affected
kernel-doc as a component of Red Hat Enterprise Linux 10 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-doc
- none available: Affected
kernel-rt-64k-debug-modules-core as a component of Red Hat Enterprise Linux 10 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-rt-64k-debug-modules-core
- none available: Affected
kernel-rt-debug-modules-extra as a component of Red Hat Enterprise Linux 10 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-rt-debug-modules-extra
- none available: Affected
kernel-zfcpdump-devel-matched as a component of Red Hat Enterprise Linux 10 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-zfcpdump-devel-matched
- none available: Affected
kernel-debug as a component of Red Hat Enterprise Linux 6 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-debug
- no fix planned: Out of support scope
kernel-64k as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-64k
- none available: Affected
kernel-64k-modules-core as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-64k-modules-core
- none available: Affected
kernel-debug-modules-extra as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-debug-modules-extra
- none available: Affected
kernel-modules-extra as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-modules-extra
- none available: Affected
kernel-rt-64k-debug-modules-internal as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-rt-64k-debug-modules-internal
- none available: Affected
kernel-rt-debug-devel as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-rt-debug-devel
- none available: Affected
kernel-rt-modules-extra as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-rt-modules-extra
- none available: Affected
kernel-zfcpdump-devel-matched as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-zfcpdump-devel-matched
- 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
bpftool 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-2026-98374 · Updated 2026-10-24T14:27:31+00:00kernel-debug-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-debug-devel
Red Hat · CVE-2026-98374 · Updated 2026-10-24T14:27:31+00:00kernel-kdump-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-kdump-devel
Red Hat · CVE-2026-98374 · Updated 2026-10-24T14:27:31+00:00kernel-rt-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-rt-devel
Red Hat · CVE-2026-98374 · Updated 2026-10-24T14:27:31+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-2026-98374 · Updated 2026-10-24T14:27:31+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-2026-98374 · Updated 2026-10-24T14:27:31+00:00kernel-abi-stablelists as a component of Red Hat Enterprise Linux 8 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-abi-stablelists
Red Hat · CVE-2026-98374 · Updated 2026-10-24T14:27:31+00:00kernel-debug-core as a component of Red Hat Enterprise Linux 8 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-debug-core
Red Hat · CVE-2026-98374 · Updated 2026-10-24T14:27:31+00:00kernel-doc as a component of Red Hat Enterprise Linux 8 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-doc
Red Hat · CVE-2026-98374 · Updated 2026-10-24T14:27:31+00:00kernel-modules-internal as a component of Red Hat Enterprise Linux 8 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-modules-internal
Red Hat · CVE-2026-98374 · Updated 2026-10-24T14:27:31+00:00kernel-rt-debug-devel as a component of Red Hat Enterprise Linux 8 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-rt-debug-devel
Red Hat · CVE-2026-98374 · Updated 2026-10-24T14:27:31+00:00kernel-rt-devel as a component of Red Hat Enterprise Linux 8 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-rt-devel
Red Hat · CVE-2026-98374 · Updated 2026-10-24T14:27:31+00:00kernel-rt-selftests-internal as a component of Red Hat Enterprise Linux 8 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-rt-selftests-internal
Red Hat · CVE-2026-98374 · Updated 2026-10-24T14:27:31+00:00kernel-tools-libs-devel as a component of Red Hat Enterprise Linux 8 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-tools-libs-devel
Red Hat · CVE-2026-98374 · Updated 2026-10-24T14:27:31+00:00kernel-zfcpdump-modules-extra as a component of Red Hat Enterprise Linux 8 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-zfcpdump-modules-extra
Red Hat · CVE-2026-98374 · Updated 2026-10-24T14:27:31+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-2026-98374 · Updated 2026-10-24T14:27:31+00:00
All CVSS metrics
- HIGH 8.8 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - HIGH 8.8 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:L/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-2026-98374.json Red Hat · CVE-2026-98374 · Updated 2026-10-24T14:27:31+00:00
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-94323 EUVD · EUVD-2026-94323
Technical & other
- https://git.kernel.org/stable/c/fad6d429651e748365e93ca54645accc212f0018CVE record · Linux · Updated 2026-10-24T14:08:34.914Z
NVD · CVE-2026-98374 · Updated 2026-10-24T14:16:39.560 - https://git.kernel.org/stable/c/c5b4da1f403a658c1c19766be2b426003ada419fCVE record · Linux · Updated 2026-10-24T14:08:34.914Z
NVD · CVE-2026-98374 · Updated 2026-10-24T14:16:39.560 - https://git.kernel.org/stable/c/71d45049b0d631dfdbf3c65305f7fca676de023bCVE record · Linux · Updated 2026-10-24T14:08:34.914Z
NVD · CVE-2026-98374 · Updated 2026-10-24T14:16:39.560 - https://git.kernel.org/stable/c/e3ea71cb1408a013ed4e8a757b815f1a919324bdCVE record · Linux · Updated 2026-10-24T14:08:34.914Z
NVD · CVE-2026-98374 · Updated 2026-10-24T14:16:39.560 - https://git.kernel.org/stable/c/631aa4cb45099f09e9385dd786bd291c6270bfc4CVE record · Linux · Updated 2026-10-24T14:08:34.914Z
NVD · CVE-2026-98374 · Updated 2026-10-24T14:16:39.560 - https://git.kernel.org/stable/c/0f87720c7e4bcab07c24888b3cf12bfe857bb90eCVE record · Linux · Updated 2026-10-24T14:08:34.914Z
NVD · CVE-2026-98374 · Updated 2026-10-24T14:16:39.560 - https://git.kernel.org/stable/c/fe99bbeee5c5dbd3abc30721a8079ced59649d97CVE record · Linux · Updated 2026-10-24T14:08:34.914Z
NVD · CVE-2026-98374 · Updated 2026-10-24T14:16:39.560 - https://access.redhat.com/security/cve/CVE-2026-98374 Red Hat · CVE-2026-98374 · Updated 2026-10-24T14:27:31+00:00
- https://bugzilla.redhat.com/show_bug.cgi?id=2547433 Red Hat · CVE-2026-98374 · Updated 2026-10-24T14:27:31+00:00
- https://www.cve.org/CVERecord?id=CVE-2026-98374 Red Hat · CVE-2026-98374 · Updated 2026-10-24T14:27:31+00:00
- https://nvd.nist.gov/vuln/detail/CVE-2026-98374 Red Hat · CVE-2026-98374 · Updated 2026-10-24T14:27:31+00:00
- https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98374.mbox Red Hat · CVE-2026-98374 · Updated 2026-10-24T14:27:31+00:00