Use After Free in FreeBSD
CVE-2026-58090
The SOCK_STREAM receive path in the unix socket implementation failed to fully detach control messages from the socket buffer before processing them. Some error paths would free those messages, leaving freed data mbufs in the receive socket buffer. An unprivileged local user can exploit this use-after-free to escalate privileges.
Vulnerability class: Use-After-Free
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.002 (4.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 4th percentile — 4.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.000
Affected products
- FreeBSD — versions 15.0, 15.1
Weakness classification (CWE)
References
- security.freebsd.org/advisories/FreeBSD-SA-26:57.unix.asc (vendor-advisory, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-58090?
- CVE-2026-58090 is a high-severity vulnerability in FreeBSD, classified under Use After Free. CVSS score: 7.8/10. Published 2026-08-26.
- How severe is CVE-2026-58090?
- High severity. CVSS v3 base score is 7.8 out of 10.