CVE-2026-98255
Description
In the Linux kernel, the following vulnerability has been resolved: tcp: exclude old ACKs from tcp fast path Exclude old ACKs before SND.UNA from the tcp fast path as well as ACKs after SND.NXT. Such ACKs will fall through to the slow path, where tcp_ack() performs the appropriate validation and challenge ACK handling according to RFC5961 and Commit 3d501dd326fb1c7 ("tcp: do not accept ACK of bytes we never sent"). This prevents old ACKs from being accepted or modifying connection state as part of the fast path before appropriate ACK validation is applied. In particular, this prevents payload carried by a segment with an excessively old ACK from advancing RCV.NXT before the ACK is rejected.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
Propose a mitigation on Community Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
References
- https://git.kernel.org/stable/c/07cacab90290f795bad2e566790f4ba8e84cdf5f
- https://git.kernel.org/stable/c/1c8448db5cf35a13d82b0c9004ffdb49358883e7
- https://git.kernel.org/stable/c/6eb9b697f50b73b9684e466c1e97f4ca8e947a59
- https://git.kernel.org/stable/c/8205ac5ddb42a1843fa8d6a8c295b5c7f4f8c6ed
- https://git.kernel.org/stable/c/8309dc2cc360056aa9cd2acfbfc25930798c3b66
- https://git.kernel.org/stable/c/b86e1e5a4bbcbbccde8b7a3d3486604b581f6628
- https://git.kernel.org/stable/c/f81e6c3fb06327bc49cdd6e559845293ba06a704
- https://git.kernel.org/stable/c/ff037920c688ae6ca1153fec01e90e6782712455
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.