CVE-2026-58098
Received
Received - Intake
Semop Sequence Number Wrap-Around in FreeBSD Kernel
Vulnerability report for CVE-2026-58098, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-10-15
Last updated on: 2026-10-15
Assigner: FreeBSD
Description
Description
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 Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| FreeBSD | FreeBSD | 15.1-RELEASE |
| FreeBSD | FreeBSD | 15.0-RELEASE |
| FreeBSD | FreeBSD | 14.5-RELEASE |
| FreeBSD | FreeBSD | 14.4-RELEASE |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-787 | The product writes data past the end, or before the beginning, of the intended buffer. |
