CVE-2026-58098
When semop(2) blocks waiting for a semaphore condition, it releases the per-set lock and sleeps.
Published Oct 15, 2026 · updated Oct 15, 2026 · FreeBSD FreeBSD
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.
Code
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Timeline
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Oct 15, 2026 · NIST NVD
Detected
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, th
Oct 15, 2026 · NIST NVD
Updated
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, th
Affected
- vendor FreeBSD FreeBSDversion unspecified
Sources
- CIRCL Vulnerability LookupVulnerability recordCVE-2026-58098
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 on
vulnerability.circl.lu - CVE.orgVulnerability recordCVE-2026-58098
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-58098
30-day exploitation probability 0.2%
first.org - NIST NVDVulnerability recordCVE-2026-58098
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
nvd.nist.gov