{"id":"CVE-2026-86871","title":"An integer underflow was addressed with improved input validation","summary":"An integer underflow was addressed with improved input validation. This issue is fixed in macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7. An attacker with control of a network file server may be able to cause unexpected syste…","severity":"medium","cvss":5.9,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","cvssSource":"adp","vendor":"Apple","product":"macOS","affected":["macOS < 15.8","macOS < 26.7","macOS < 27"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-10-20T14:39:26.599060Z"},"published":"2026-10-20","updated":"2026-10-26","sourceUpdated":"2026-10-26T20:39:46.185Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-86871","references":[{"url":"https://support.apple.com/en-us/149035"},{"url":"https://support.apple.com/en-us/149042"},{"url":"https://support.apple.com/en-us/149043"}],"tags":["cve.org"],"epss":0.00489,"epssPercentile":0.41857,"ingestedAt":"2026-10-20T01:49:42.598Z","slug":"CVE-2026-86871","body":"## Overview\n\nAn integer underflow was addressed with improved input validation. This issue is fixed in macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7. An attacker with control of a network file server may be able to cause unexpected system termination.\n\n## Affected\n\n- `macOS < 15.8`\n- `macOS < 26.7`\n- `macOS < 27`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":33,"depthScoreParts":{"impact":32.5,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":225914,"id":"CVE-2026-86871","ts":1792509020791,"field":"cvss","old":null,"new":"5.9"},{"seq":225913,"id":"CVE-2026-86871","ts":1792509020791,"field":"severity","old":"none","new":"medium"}]}