Critical (9.8) in openbsd openbsd. EPSS 4.0% chance of exploitation in the next 30 days.
A flaw exists in OpenBSD's implementation of the stack guard page that allows attackers to bypass it resulting in arbitrary code execution using setuid binaries such as /usr/bin/at. This affects OpenBSD 6.1 and possibly earlier versions.
Severity
CVSS 3.0
9.8 critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
4.0% chance of exploitation in the next 30 days; higher than 90% of CVEs (scores of 2026-10-31)