CVE-2026-58098Heap out-of-bounds access in semop(2)
Updated under an hour ago ()
Does this affect you?
It affects FreeBSD. Add what you run to find out whether that includes you.
EPSS puts the chance of exploitation in the next 30 days at 0.18%, higher than 7% of scored CVEs.
Do this next
Free account, 1 product
When semop(2) blocks waiting for a semaphore condition, it releases the per-set lock and sleeps. Upon waking, it checks the sequence number embedded in the semaphore set's IPC identifier to detect whether the set was removed while the caller was asleep. This sequence number is only 15 bits wide. If enough semaphore sets are created and destroyed in the same table slot while a caller is blocked, the counter wraps around, and semop(2) may falsely conclude that the original set still exists. The subsequent access to a semaphore within the set may then be out of bounds. An unprivileged local user can trigger an out-of-bounds access on kernel heap memory, potentially leading to privilege escalation.
- CVSS
- 8.4 HIGH (v3.1, CISA ADP)CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- CWE-787
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- 0.18% (percentile 7)
- Assigned by
- freebsd
- NVD analysis
- Undergoing Analysis
- Record last updated
- Oct 16, 2026
- First seen by InfoSec Signals
- Oct 15, 2026
Affected products
FreeBSD FreeBSD freebsd:freebsd (from the name) | from 15.1-RELEASE before p4; from 15.0-RELEASE before p14; from 14.5-RELEASE before p1; from 14.4-RELEASE before p10 | CNA record |
References
- https://security.freebsd.org/advisories/FreeBSD-SA-26:64.sysvsem.ascvendor-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.