Use-after-free in Linux kernel - CVE-2026-31657
Published: April 25, 2026
Vulnerability identifier: #VU127735
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-31657
CWE-ID: CWE-416
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 use-after-free in the batman-adv BLA claim handling code when processing netlink claim dump operations or checking claims. A local user can trigger concurrent claim updates and reader access to dereference a freed backbone gateway pointer to cause a denial of service.
How to mitigate CVE-2026-31657
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/1f2dc36c297d27733f1b380ea644cf15a361bd7b
- https://git.kernel.org/stable/c/2f55b58b5a0bbed192d60c444a45a49cdf1b545f
- https://git.kernel.org/stable/c/4dee4c0688443aaf5bbec74aa203c851d1d53c35
- https://git.kernel.org/stable/c/7962b522222628596ca9ecc8722efc95367aadbd
- https://git.kernel.org/stable/c/82d8701b2c930d0e96b0dbc9115a218d791cb0d2
- https://git.kernel.org/stable/c/f4858832ddef2f39f21e30b7226bbcd3c4b2bc96