Quick answers
- Is CVE-2026-58098 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-58098 being exploited in the wild.
- How severe is CVE-2026-58098?
- High severity, with a CVSS score of 8.4, published 15 October 2026.
- Which products and versions are affected?
- Freebsd All supported versions prior to the correction dates.
- Is there a fix for CVE-2026-58098?
- Yes: fixed in FreeBSD 15.1-RELEASE-p4, 15.0-RELEASE-p14, 14.5-RELEASE-p1, 14.4-RELEASE-p10, stable/15, stable/14. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-58098 attacked?
- It is attacked with local access, in an operating system.
- Am I affected by CVE-2026-58098?
- Check whether you run Freebsd at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- Fixed in: FreeBSD 15.1-RELEASE-p4, 15.0-RELEASE-p14, 14.5-RELEASE-p1, 14.4-RELEASE-p10, stable/15, stable/14
Technical details
When semop(2) wakes from blocking, it uses a 15-bit sequence number embedded in the IPC identifier to verify the semaphore set still exists. If enough sets are created and destroyed in the same slot while a caller is blocked, the counter wraps and semop may access freed or unrelated heap memory out of bounds. The vulnerability requires local access and involves a timing race condition, with successful exploitation potentially allowing privilege escalation.
Affected products
- FreeBSD FreeBSD All supported versions prior to the correction dates
Timeline
- 2026-09-29: disclosed: FreeBSD Security Advisory SA-26:64 published
- 2026-09-29: patched: Patches released for all supported branches