CVE-2026-45259 json
sigqueue(2) missing capability mode restriction
published 2026-06-27 4 mo ago modified 2026-07-01 4 mo ago also EUVD-2026-39963
- cvss
- 6.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.1%
- EPSS 0.1% chance of exploitation in 30 days, percentile 2%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- FreeBSD FreeBSD p6, p10, p15
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 4 mo ago
Exploit prediction
0.13% chance of exploitation in the next 30 days, higher than 2% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CISA ADP | 3.1 | 6.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H |
| CNA | 3.1 | 6.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H |
Affected products
- FreeBSD FreeBSD
Classification
- Weakness
-
- CWE-266 Incorrect Privilege Assignment
References
-
security.freebsd.org
/advisories/FreeBSD-SA-26:28.capsicum.asc
vendor-advisory
Sources
- CVE List CVE-2026-45259
- NVD CVE-2026-45259
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