Use-after-free in Linux kernel - CVE-2026-74478
Published: August 16, 2026
Vulnerability identifier: #VU143305
CSH Severity: Medium
CVSS v4: 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]
CVE-ID: CVE-2026-74478
CWE-ID: CWE-416
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
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.
Affected software
Linux kernel
Debian Linux
linux (Debian package)
Debian Linux
linux (Debian package)
How to mitigate CVE-2026-74478
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
linux (Debian package) - update to 6.12.105-1
linux (Debian package) - update to 6.12.105-1
External 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