CVE-2026-45889mptcp: do not account for OoO in mptcp_rcvbuf_grow()
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Analyzed
- Record last updated
- May 27, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from e118cdc34dd109562b64f6a397f68cd33b041d5b before fb7bf00b04a6b48859f52035d4e745848c2b4c79; from e118cdc34dd109562b64f6a397f68cd33b041d5b before 400ee4854adef1e4983812a3decf6717ea020136; from e118cdc34dd109562b64f6a397f68cd33b041d5b before 6b329393502e5857662b851a13f947209c588587 | CNA record |
linux linux_kernel linux:linux_kernel | from 6.18 before 6.18.14; from 6.19 before 6.19.4 | NVD |
References
- https://git.kernel.org/stable/c/fb7bf00b04a6b48859f52035d4e745848c2b4c79patch
- https://git.kernel.org/stable/c/400ee4854adef1e4983812a3decf6717ea020136patch
- https://git.kernel.org/stable/c/6b329393502e5857662b851a13f947209c588587patch
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.