Use-after-free in Linux kernel - CVE-2026-63831
Published: July 20, 2026
Vulnerability identifier: #VU138822
CSH Severity: Low
CVSS v4: 6.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-63831
CWE-ID: CWE-416
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to cause a denial of service or corrupt data.
The vulnerability exists due to use-after-free in the mac802154 llsec crypto processing in net/mac802154/llsec.c when performing in-place cryptographic transformations on shared skb data. A local user can trigger concurrent 802.15.4 traffic with security enabled to cause a denial of service or corrupt data.
The issue can affect both RX and TX paths when skb data buffers are shared across clones.
Affected software
Linux kernel
How to mitigate CVE-2026-63831
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
External References
- https://git.kernel.org/stable/c/3a2b378b3a9ca75d3518d879148d2ad25b5714a9
- https://git.kernel.org/stable/c/7a831bcd0486788283ef35e396d4282ee01bb0d5
- https://git.kernel.org/stable/c/84a04eb5b210643bd67aab81ff805d32f62aa865
- https://git.kernel.org/stable/c/86d531337ea1ba02d9f2bc830d07c683d9bfaade
- https://git.kernel.org/stable/c/993fd674fe85d114e6a8d3963033d4fbbc2170a8
- https://git.kernel.org/stable/c/bd968bdd568beacfdf98ec537a87527e85f1d0cf
- https://git.kernel.org/stable/c/e28e7fd34c449028325322a3f5127b92594b7396
- https://git.kernel.org/stable/c/ff976ef7c39199ebff33c18034636595016db9f0