sigqueue(2) missing capability mode restriction

Summary

CVECVE-2026-45259
StatePUBLISHED
Assignerfreebsd
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-06-27 09:16:22 UTC
Updated2026-07-01 14:04:51 UTC
Descriptionsigqueue(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.

Risk And Classification

Primary CVSS: v3.1 6.5 MEDIUM from ADP

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

EPSS: 0.000920000 probability, percentile 0.006630000 (date 2026-07-04)

Problem Types: CWE-266 | CWE-266 CWE-266: Incorrect Privilege Assignment


VersionSourceTypeScoreSeverityVector
3.1ADPDECLARED6.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
3.1134c704f-9b21-4f2e-91b3-4a467353bcc0Secondary6.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H

CVSS v3.1 Breakdown

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Changed
Confidentiality
None
Integrity
None
Availability
High

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

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Operating System Freebsd Freebsd 14.3 - All All
Operating System Freebsd Freebsd 14.3 p1 All All
Operating System Freebsd Freebsd 14.3 p10 All All
Operating System Freebsd Freebsd 14.3 p11 All All
Operating System Freebsd Freebsd 14.3 p12 All All
Operating System Freebsd Freebsd 14.3 p13 All All
Operating System Freebsd Freebsd 14.3 p14 All All
Operating System Freebsd Freebsd 14.3 p2 All All
Operating System Freebsd Freebsd 14.3 p3 All All
Operating System Freebsd Freebsd 14.3 p4 All All
Operating System Freebsd Freebsd 14.3 p5 All All
Operating System Freebsd Freebsd 14.3 p6 All All
Operating System Freebsd Freebsd 14.3 p7 All All
Operating System Freebsd Freebsd 14.3 p8 All All
Operating System Freebsd Freebsd 14.3 p9 All All
Operating System Freebsd Freebsd 14.4 - All All
Operating System Freebsd Freebsd 14.4 p1 All All
Operating System Freebsd Freebsd 14.4 p2 All All
Operating System Freebsd Freebsd 14.4 p3 All All
Operating System Freebsd Freebsd 14.4 p4 All All
Operating System Freebsd Freebsd 14.4 p5 All All
Operating System Freebsd Freebsd 15.0 - All All
Operating System Freebsd Freebsd 15.0 p1 All All
Operating System Freebsd Freebsd 15.0 p2 All All
Operating System Freebsd Freebsd 15.0 p3 All All
Operating System Freebsd Freebsd 15.0 p4 All All
Operating System Freebsd Freebsd 15.0 p5 All All
Operating System Freebsd Freebsd 15.0 p6 All All
Operating System Freebsd Freebsd 15.0 p7 All All
Operating System Freebsd Freebsd 15.0 p8 All All
Operating System Freebsd Freebsd 15.0 p9 All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA FreeBSD FreeBSD affected 15.0-RELEASE p10 release Not specified
CNA FreeBSD FreeBSD affected 14.4-RELEASE p6 release Not specified
CNA FreeBSD FreeBSD affected 14.3-RELEASE p15 release Not specified

References

ReferenceSourceLinkTags
security.freebsd.org/advisories/FreeBSD-SA-26:28.capsicum.asc [email protected] security.freebsd.org Vendor Advisory
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Ed Maste (en)

© CVE.report 2026

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report