Improper locking in Linux kernel - CVE-2026-98301
Published: October 7, 2026
Vulnerability identifier: #VU153715
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-2026-98301
CWE-ID: CWE-667
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 locking in br_mst_set_state() when processing nonzero MSTI state changes through netlink. A local user can request these state changes to cause a denial of service.
The switchdev_port_attr_set() call invokes a blocking notifier chain that may sleep while an RCU read-side critical section is active. Nonzero MSTI changes are processed with the RTNL lock held.
Affected software
Linux kernel
Debian Linux
linux (Debian package)
Debian Linux
linux (Debian package)
How to mitigate CVE-2026-98301
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
linux (Debian package) - update to 6.12.113-1
linux (Debian package) - update to 6.12.113-1
External References
- https://git.kernel.org/stable/c/18a6fe05fb6e18de29fa90d388bb34044114b3d8
- https://git.kernel.org/stable/c/6b431b63219853eef4054e2f1cb073d2ca2059b4
- https://git.kernel.org/stable/c/abf734d150c61acfdfee102169d0e5d1c482e285
- https://git.kernel.org/stable/c/b9661fd2423fc25e91e0517ecc0b6156ad83e3a8
- https://git.kernel.org/stable/c/c40ed3e884c8dc0350f26484030438ef24208ff1
- https://git.kernel.org/stable/c/d5c4ee1fa4e83a12afc051c831936cd8e006cde3