SB20260528244 - Improper input validation in Linux kernel openvswitch
Published: May 28, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Improper input validation (CVE-ID: CVE-2026-45840)
CWE-ID: CWE-20 - Improper input validation
CVSSv4: 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
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to improper input validation in the openvswitch vport netlink reply helpers when handling a crafted upcall PID array in vport mutation operations. A local user can supply an oversized PID array to trigger a kernel BUG and cause a denial of service.
On systems with unprivileged user namespaces enabled, the issue is reachable via unshare -Urn.
Remediation
Install update from vendor's website.
References
- https://git.kernel.org/stable/c/1d6c02b86329883aa467a3a61f8d34369db73a2f
- https://git.kernel.org/stable/c/2091c6aa0df6aba47deb5c8ab232b1cb60af3519
- https://git.kernel.org/stable/c/f99ac36b5d7c719d08a69fcdecce40f78a874e15
- https://git.kernel.org/stable/c/f9ef3db77a383d66847fd082c2b437d8ae4d9c63
- https://git.kernel.org/stable/c/fa6e90bc443bed8dc0d55bc5ea5b27ffdfe37704