CVE-2026-63971: Linux kernel · sctp: fix race between sctp_wait_for_connect and peeloff
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in f14fe6395a8b3d961a61e138ad7b36ba3626dd4e : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in f14fe6395a8b3d961a61e138ad7b36ba3626dd4e, bcfeac79af740735ace44008b4a11b8e5add20f5, 68667ee4c7dadf7f63167234e2a1af09b3f7874e +5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 19 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
Description
In the Linux kernel, the following vulnerability has been resolved: sctp: fix race between sctp_wait_for_connect and peeloff sctp_wait_for_connect() drops and re-acquires the socket lock while waiting for the association to reach ESTABLISHED state. During this window, another thread can peeloff the association to a new socket via getsockopt(SCTP_SOCKOPT_PEELOFF), changing asoc->base.sk. After re-acquiring the old socket lock, sctp_wait_for_connect() returns success without noticing the migration — the caller then accesses the association under the wrong lock in sctp_datamsg_from_user(). Add the same sk != asoc->base.sk check that sctp_wait_for_sndbuf() already has, returning an error if the association was migrated while we slept.
References
- git.kernel.org/stable/c/0e0d5bc76fd4267a71334fcc8f1a5fbcf997845d (opens in a new tab)
- git.kernel.org/stable/c/bcfeac79af740735ace44008b4a11b8e5add20f5 (opens in a new tab)
- git.kernel.org/stable/c/8e9b56051d24540cfbf39194618708c4a7633549 (opens in a new tab)
- git.kernel.org/stable/c/634a9af8a26a84d8b0d7b3b643204b344b42d9fb (opens in a new tab)
- git.kernel.org/stable/c/7d2038d4b80166f7bead8d07eba3b97405816c21 (opens in a new tab)
- git.kernel.org/stable/c/68667ee4c7dadf7f63167234e2a1af09b3f7874e (opens in a new tab)
- git.kernel.org/stable/c/6140cfa721451fa6e18e134e709703c2bf34d0fb (opens in a new tab)
- git.kernel.org/stable/c/f14fe6395a8b3d961a61e138ad7b36ba3626dd4e (opens in a new tab)