Race condition in Linux kernel - CVE-2026-63971
Published: July 20, 2026
Vulnerability identifier: #VU138673
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-63971
CWE-ID: CWE-362
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a race condition in sctp_wait_for_connect() in the SCTP socket implementation when waiting for an association to reach established state while another thread peels off the association to a new socket. A local user can trigger association migration during this window to cause a denial of service.
Exploitation requires concurrent access from another thread while the socket lock is dropped and re-acquired.
How to mitigate CVE-2026-63971
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/0e0d5bc76fd4267a71334fcc8f1a5fbcf997845d
- https://git.kernel.org/stable/c/6140cfa721451fa6e18e134e709703c2bf34d0fb
- https://git.kernel.org/stable/c/634a9af8a26a84d8b0d7b3b643204b344b42d9fb
- https://git.kernel.org/stable/c/68667ee4c7dadf7f63167234e2a1af09b3f7874e
- https://git.kernel.org/stable/c/7d2038d4b80166f7bead8d07eba3b97405816c21
- https://git.kernel.org/stable/c/8e9b56051d24540cfbf39194618708c4a7633549
- https://git.kernel.org/stable/c/bcfeac79af740735ace44008b4a11b8e5add20f5
- https://git.kernel.org/stable/c/f14fe6395a8b3d961a61e138ad7b36ba3626dd4e