CVE-2026-45259 Details
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.
A vulnerability exists in the FreeBSD Capsicum framework, specifically in the handling of the sigqueue(2) function within capability mode. While sigqueue(2) was allowed in capability mode, the implementation failed to restrict signal delivery to the calling process's own PID. This oversight allows a process in capability mode to send signals to any process it can signal under standard Unix permissions, bypassing the intended Capsicum sandbox restrictions. As a result, a compromised sandboxed process could disrupt other processes by sending signals such as SIGKILL or SIGSTOP. This issue affects all supported FreeBSD versions.
Users can upgrade to a supported FreeBSD stable or release/security branch dated after the correction date. Instructions for updating via base system packages, binary distribution sets, or source code patches are available in the FreeBSD Security Advisory.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Jun 29, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://security.freebsd.org/advisories/FreeBSD-SA-26:28.capsicum.asc | [email protected] | Vendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-266 | Incorrect Privilege Assignment | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| freebsd freebsd | 14.3 - 14.3 p1 14.3 p10 14.3 p11 14.3 p12 14.3 p13 14.3 p14 14.3 p2 14.3 p3 14.3 p4 14.3 p5 14.3 p6 14.3 p7 14.3 p8 14.3 p9 14.4 - 14.4 p1 14.4 p2 14.4 p3 14.4 p4 14.4 p5 15.0 - 15.0 p1 15.0 p2 15.0 p3 15.0 p4 15.0 p5 15.0 p6 15.0 p7 15.0 p8 15.0 p9 |
CPE
Remediation
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Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 1, 2026 | Initial Analysis | [email protected] |
| Jun 29, 2026 | CVE Modified | CISA-ADP |
| Jun 27, 2026 | New CVE Received | [email protected] |