Uninitialized data exposure in Linux kernel netfilter conntrack
Key facts
- Attack vector
- —
- Privileges required
- —
- User interaction
- —
- Attack complexity
- —
- Impact type
- —
- Confidentiality · integrity · availability
- —
- Fix status
- Partial Red Hat: 6 without a fix
No CVSS vector from any source. Fix status from CNA and Red Hat.
Summary
The Linux kernel from 3.4 before the fixed versions is affected. In the netfilter connection tracking expectation code, newly allocated expectation objects are not zeroed, so uninitialized kernel memory can be leaked to userspace through ctnetlink.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Description from the CNA
In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_expect: zero at allocation time There are occasional LLM hints wrt. leaking uninitialized data to userspace via ctnetlink. Just zero at allocation time, expectations are not frequently used these days. Intentionally keeps _init as-is because we could theoretically support re-init, so add the missing exp->dir there.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
Update the Linux kernel to a fixed version for your branch: 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.111, 6.18.53 or 7.2. Red Hat has no fix planned for Red Hat Enterprise Linux 6. The sources list no fixed version for Red Hat Enterprise Linux 7, 8, 9, 10 and Red Hat OpenShift Container Platform 4.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
- Fix · CNA Linux (Linux) Fixed in 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.111, 6.18.53, 7.2
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet: Fix deferred |
Timeline
- 2026-10-23 Threatist record created from CVE-2026-98873
- 2026-10-23 Alias added: GHSA-9v8r-rm7r-2xx4
- 2026-10-26 Fix available: Linux/Linux@0 · CNA
- 2026-10-26 Affected versions changed · Red Hat
- 2026-10-26 CVSS score added · Red Hat
References
Other 7
- https://git.kernel.org/stable/c/39cb6ff947c16a576ea68c5f272e634acdcb0085
- https://git.kernel.org/stable/c/90545aa07a183887e9d72ce573c18e08f62e2c91
- https://git.kernel.org/stable/c/9c11d7ea5ff4dbe162e79f00188814ef5483c295
- https://git.kernel.org/stable/c/b7f3ee925aee9f1f547d539bc03c35433c238958
- https://git.kernel.org/stable/c/824397af7bfe14edad374c64253dae0187ca623d
- https://git.kernel.org/stable/c/a39ecb856514274c80d0fac4d128dba6b266a8ed
- https://git.kernel.org/stable/c/241ccd2fed9051db443aadce248fc0ab30f55e97
More Linux vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2021-02452 Incorrect authorization in Ubuntu linux kernel KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
Sources
- CVE-2026-98873 · CVE Program
- CVE-2026-98873 · NVD
- FIRST EPSS
- GHSA-9v8r-rm7r-2xx4 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-98873 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences