{"id":"CVE-2026-92040","title":"Use-after-free in the JavaScript: WebAssembly component","summary":"Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 156 and Thunderbird 156.","severity":"high","cvss":8.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","cwe":["CWE-416","CWE-825"],"vendor":"Mozilla","product":"Firefox","affected":["Firefox","Thunderbird"],"published":"2026-09-15","updated":"2026-09-20","sourceUpdated":"2026-09-20T01:16:35.913","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-92040","references":[{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=2024248","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-90/","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-94/","label":"security@mozilla.org"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-92040.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-92040"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2533763"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-92040"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-92040"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-90/#CVE-2026-92040"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-94/#CVE-2026-92040"}],"tags":["nvd","cve.org","csaf","vex","red-hat","score-dispute"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-09-20T00:19:32.366879Z"},"epss":0.00301,"epssPercentile":0.22957,"scores":{"nvd":8.8,"vendor":6.1,"adp":8.8},"ingestedAt":"2026-09-15T12:36:50.186Z","slug":"CVE-2026-92040","body":"## Overview\n\nUse-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 156 and Thunderbird 156.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · updated 2026-09-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-92040.json)","depth":"twilight","depthScore":48,"depthScoreParts":{"impact":48.4,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":207875,"id":"CVE-2026-92040","ts":1789870390532,"field":"cvss","old":"6.1","new":"8.8"},{"seq":207874,"id":"CVE-2026-92040","ts":1789870390532,"field":"severity","old":"medium","new":"high"},{"seq":206350,"id":"CVE-2026-92040","ts":1789663221883,"field":"cvss","old":null,"new":"6.1"},{"seq":206349,"id":"CVE-2026-92040","ts":1789663221883,"field":"severity","old":"none","new":"medium"}]}