FreeBSD setcred Stack Buffer Overflow: Privilege Escalation (CVE-2026-45250)
CVE-2026-45250 Published on May 21, 2026

Stack buffer overflow via setcred(2)
The setcred(2) system call is only available to privileged users. However, before the privilege level of the caller is checked, the user-supplied list of supplementary groups is copied into a fixed-size kernel stack buffer without first validating its length. If the supplied list exceeds the capacity of that buffer, a stack buffer overflow occurs. Because the bounds check on the supplementary groups list occurs after the kernel stack buffer has already been written, an unprivileged local user may trigger the overflow without holding any special privilege. Successful exploitation may allow an attacker to execute arbitrary code in the context of the kernel, allowing an unprivileged local user to gain elevated privileges on the affected system.

Vendor Advisory NVD

Weakness Type

What is a Stack Overflow Vulnerability?

A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).

CVE-2026-45250 has been classified to as a Stack Overflow vulnerability or weakness.


Products Associated with CVE-2026-45250

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Affected Versions

FreeBSD: