{"id":"CVE-2026-109776","title":"Race condition in the XPCOM component","summary":"Race condition in the XPCOM component. This vulnerability was fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.","severity":"medium","cvss":4.2,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N","cwe":["CWE-362"],"vendor":"Mozilla","product":"Firefox","affected":["Firefox","Thunderbird"],"published":"2026-10-13","updated":"2026-10-15","sourceUpdated":"2026-10-15T20:17:08.393","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-109776","references":[{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=2069395","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-106/","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-108/","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-109/","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-110/","label":"security@mozilla.org"}],"tags":["nvd","cve.org"],"epss":0.00145,"epssPercentile":0.03748,"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-10-15T19:58:15.850458Z"},"ingestedAt":"2026-10-13T13:27:04.016Z","slug":"CVE-2026-109776","body":"## Overview\n\nRace condition in the XPCOM component. This vulnerability was fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":23,"depthScoreParts":{"impact":23.1,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":222700,"id":"CVE-2026-109776","ts":1792097054058,"field":"cvss","old":null,"new":"4.2"},{"seq":222699,"id":"CVE-2026-109776","ts":1792097054058,"field":"severity","old":"none","new":"medium"}]}