Improper update of reference count in Linux kernel - CVE-2026-74735
Published: August 27, 2026
Vulnerability identifier: #VU145993
CSH Severity: Low
CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-74735
CWE-ID: CWE-911
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to improper reference counting in the l2tp seq_file handlers for /proc/net/pppol2tp and /sys/kernel/debug/l2tp/tunnels when closing the file before reading to end-of-file. A local user can close the file early to cause a denial of service.
The issue occurs because tunnel and session references kept in seq_file private iteration state are not dropped on release.
Affected software
Linux kernel
How to mitigate CVE-2026-74735
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3