CVE-2026-45889
Description
In the Linux kernel, the following vulnerability has been resolved: mptcp: do not account for OoO in mptcp_rcvbuf_grow() MPTCP-level OoOs are physiological when multiple subflows are active concurrently and will not cause retransmissions nor are caused by drops. Accounting for them in mptcp_rcvbuf_grow() causes the rcvbuf slowly drifting towards tcp_rmem[2]. Remove such accounting. Note that subflows will still account for TCP-level OoO when the MPTCP-level rcvbuf is propagated. This also closes a subtle and very unlikely race condition with rcvspace init; active sockets with user-space holding the msk-level socket lock, could complete such initialization in the receive callback, after that the first OoO data reaches the rcvbuf and potentially triggering a divide by zero Oops.
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 โ if you've already worked around this in production โ publish your fix to the community-verified tier.
โ Propose a mitigation on Community โ Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| debian | bookworm | fixed | 0 |
| debian | bullseye | fixed | 0 |
| debian | forky | fixed | 6.18.14-1 |
| debian | sid | fixed | 6.18.14-1 |
| debian | trixie | fixed | 0 |
| sles | affected | |
References
- https://git.kernel.org/stable/c/fb7bf00b04a6b48859f52035d4e745848c2b4c79
- https://git.kernel.org/stable/c/400ee4854adef1e4983812a3decf6717ea020136
- https://git.kernel.org/stable/c/6b329393502e5857662b851a13f947209c588587
- https://security-tracker.debian.org/tracker/CVE-2026-45889
- https://www.suse.com/security/cve/CVE-2026-45889.html
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.