CVE-2026-45259 — MEDIUM (6.5)

Vulnerability Description

sigqueue(2) was marked as permitted in capability mode with the introduction of Capsicum in 2011, but the implementation of kern_sigqueue did not include a capability mode check restricting signal delivery to the calling process's own PID. A process in capability mode can use sigqueue(2) to send signals to any process it could signal following standard Unix permissions, bypassing the Capsicum sandbox restriction. A compromised sandboxed process could interfere with other processes, for example by sending SIGKILL or SIGSTOP. This could be any process running as the same user, or any process, for a superuser sandboxed process.

CVSS Score

6.5

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

CHANGED

Confidentiality

NONE

Integrity

NONE

Availability

HIGH

Affected Products

Vendor	Product	Versions
Freebsd	Freebsd	14.3

Related Weaknesses (CWE)

CWE-266

References

https://security.freebsd.org/advisories/FreeBSD-SA-26:28.capsicum.ascVendor Advisory

FAQ

What is CVE-2026-45259?

CVE-2026-45259 is a vulnerability with a CVSS score of 6.5 (MEDIUM). sigqueue(2) was marked as permitted in capability mode with the introduction of Capsicum in 2011, but the implementation of kern_sigqueue did not include a capability mode check restricting signal del...

How severe is CVE-2026-45259?

CVE-2026-45259 has been rated MEDIUM with a CVSS base score of 6.5/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-45259?

Check the references section above for vendor advisories and patch information. Affected products include: Freebsd Freebsd.