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.

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No CVSS v3.1

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
FreeBSD FreeBSD unknown
Version Status Constraints
15.0-RELEASE affected < p10
14.4-RELEASE affected < p6
14.3-RELEASE affected < p15

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Fixes

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Workaround

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References
Link Providers
https://security.freebsd.org/advisories/FreeBSD-SA-26:28.capsicum.asc cve-icon
History

Sat, 27 Jun 2026 09:15:00 +0000

Type Values Removed Values Added
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.
Title sigqueue(2) missing capability mode restriction
Weaknesses CWE-266
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: freebsd

Published:

Updated: 2026-06-27T08:59:17.853Z

Reserved: 2026-05-11T16:27:44.892Z

Link: CVE-2026-45259

cve-icon Vulnrichment

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cve-icon NVD

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cve-icon Redhat

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cve-icon OpenCVE Enrichment

Updated: 2026-06-27T10:30:14Z

Weaknesses