{"id":"CVE-2026-58098","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-58098","generatedAt":"2026-10-28T10:36:26.864Z","title":"An unprivileged local user can trigger an out-of-bounds access on kernel heap memory, potentially leading to privilege escalation.","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.\n\nAn unprivileged local user can trigger an out-of-bounds access on kernel heap memory, potentially leading to privilege escalation.","published":"2026-10-15T07:18:02.000Z","lastModified":"2026-10-19T21:05:21.000Z","status":"Analyzed","sourceIdentifier":"secteam@freebsd.org","cvss":{"version":"3.1","score":8.4,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-787"],"affected":["freebsd/freebsd"],"epss":{"score":0.00114,"percentile":0.01451,"date":"2026-10-27","history":[{"date":"2026-10-15","score":0.00182,"percentile":0.07227}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.11%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"scored","label":"Newly scored","at":"2026-10-16T17:00:51.000Z","detail":{"from":null,"score":"8.4","severity":"HIGH","fromSeverity":null},"summary":"Now scored CVSS 8.4 HIGH."},{"kind":"new","label":"New CVE","at":"2026-10-15T07:18:02.000Z","detail":{"score":null,"severity":null,"publishedAt":"2026-10-15T07:18:02.250Z"},"summary":"New CVE, high severity (CVSS 8.4)."}],"references":[{"url":"https://security.freebsd.org/advisories/FreeBSD-SA-26:64.sysvsem.asc","tags":["Vendor Advisory"],"source":"secteam@freebsd.org"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-58098","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}