{"id":"CVE-2026-8956","title":"Integer overflow in the Networking: JAR component","summary":"Integer overflow in the Networking: JAR component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-190"],"vendor":"mozilla","product":"firefox","affected":["firefox < 140.11.0","firefox < 151.0.0","thunderbird < 140.11","thunderbird < 151.0.0"],"patched":["firefox 151.0.0","thunderbird 151.0.0"],"published":"2026-05-19","updated":"2026-10-14","sourceUpdated":"2026-10-14T20:10:00.190","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-8956","references":[{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=2032427","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-46/","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-48/","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-50/","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-51/","label":"security@mozilla.org"}],"tags":["nvd"],"epss":0.0064,"epssPercentile":0.49461,"ingestedAt":"2026-10-14T20:53:12.316Z","slug":"CVE-2026-8956","body":"## Overview\n\nInteger overflow in the Networking: JAR component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.\n\n## Affected\n\n- `firefox < 140.11.0`\n- `firefox < 151.0.0`\n- `thunderbird < 140.11`\n- `thunderbird < 151.0.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `firefox 151.0.0`\n- `thunderbird 151.0.0`","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}