SB20260816241 - Use-after-free in Linux kernel um drivers
Published: August 16, 2026
Security Bulletin ID
SB20260816241
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Use-after-free (CVE-ID: CVE-2026-74478)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to use-after-free in vector_mmsg_rx() when processing packets with an overlay header that fails verification. A remote attacker can send a specially crafted packet to cause a denial of service.
Only GRE and L2TPv3 transports are affected, and exploitation can be triggered on a cookie or session-id mismatch without authentication.
Remediation
Install update from vendor's website.
References
- https://git.kernel.org/stable/c/180ff4c81faf01ec4e06082c9daa7c40518ead89
- https://git.kernel.org/stable/c/4b9601595e8b6b5d18878cac0aeabc687d241111
- https://git.kernel.org/stable/c/67d58ab4f2ccf7145f3da07e025735a09c79de1b
- https://git.kernel.org/stable/c/804b681002ead233abf49a3efd681f5468a835f9
- https://git.kernel.org/stable/c/af421e9aed3920c7ac88c24daa48606c7112feca