Race condition in Linux kernel openvswitch conntrack labels
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 6 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
The openvswitch module in the Linux kernel from 4.3 before the fixed versions is affected. The ovs_ct_get_conn_labels() function can add a labels extension to a confirmed conntrack entry, which may free the extension while another CPU reads it. A local user with low privileges can reach this race, with high impact on confidentiality, integrity and availability.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
In the Linux kernel, the following vulnerability has been resolved: openvswitch: avoid reallocating confirmed conntrack labels ovs_ct_get_conn_labels() adds the labels extension when a conntrack entry does not have one. Confirmed conntracks can be read locklessly, so adding an extension may reallocate and free the extension block while another CPU accesses it. Only add the extension for unconfirmed conntracks. A confirmed conntrack without labels now fails the caller's label operation instead of reallocating its extension storage.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
Upgrade the Linux kernel to 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112, 6.18.54, 7.2.8 or 7.3, or to the fixed upstream commits. Red Hat Enterprise Linux 7, 8, 9 and 10 and Red Hat OpenShift Container Platform 4 and 5 are affected, with plan none_available.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA Linux (Linux) Fixed in 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112, 6.18.54, 7.2.8, 7.3
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat Enterprise Linux 7 | Affected | No fix yet |
| Red Hat Enterprise Linux 8 | Affected | No fix yet |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet |
Not affected: 1 product
- Red Hat Enterprise Linux 6
Timeline
- 2026-10-06 Threatist record created from CVE-2026-98251
- 2026-10-06 Alias added: GHSA-6vh8-2x3v-qcxv
- 2026-10-07 CVSS score added · CNA
- 2026-10-11 Affected versions changed · Red Hat
- 2026-10-11 CVSS score added · Red Hat
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-11-06 Affected versions changed · Red Hat
References
Other 8
- https://git.kernel.org/stable/c/4371d79ea74407fb992c985b1f94391e35bb8289
- https://git.kernel.org/stable/c/7ff688aceada1160331a789385ea146f62fbddf7
- https://git.kernel.org/stable/c/05eab8dced6bf4d3009a6eeee16ddac99047dc83
- https://git.kernel.org/stable/c/579d87ec1e1e85729a6cb2c25961e58beb78640c
- https://git.kernel.org/stable/c/2e6dd889c325abf23821e1459c3ffef59b7f0009
- https://git.kernel.org/stable/c/d16f089bd700f45d720ce989d5495e1dc3be0cf8
- https://git.kernel.org/stable/c/8c9fcc6c33950d3db551af664d1fd3d998bfee56
- https://git.kernel.org/stable/c/3f118c8217c109fd13ca61caa301d72c483897ef
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Sources
- CVE-2026-98251 · CVE Program
- CVE-2026-98251 · NVD
- FIRST EPSS
- GHSA-6vh8-2x3v-qcxv · GitHub Advisory Database · CC BY 4.0
- CVE-2026-98251 · 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