{"id":"CVE-2026-8974","title":"Memory safety bugs present in Firefox ESR 140.10 and Firefox 150","summary":"Memory safety bugs present in Firefox ESR 140.10 and Firefox 150. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerab…","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-119"],"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":"2026-07-23","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-8974","references":[{"url":"https://bugzilla.mozilla.org/buglist.cgi?bug_id=1784128%2C1883230%2C1983677%2C2022390%2C2023116%2C2023657%2C2024255%2C2024418%2C2024441%2C2024447%2C2024966%2C2025412%2C2025467%2C2025940%2C2025950%2C2025956%2C2026284%2C2027247%2C2027255%2C2027288%2C2027306%2C2027322%2C2027332%2C2027333%2C2028266%2C2028292%2C2028319%2C2028526%2C2028870%2C2028876%2C2028882%2C2029062%2C2029309%2C2029414%2C2029422%2C2029428%2C2029447%2C2029732%2C2029785%2C2029793%2C2029813%2C2029899%2C2031028%2C2031457%2C2032039%2C2033610%2C2033854%2C2034498%2C2034628%2C2034978%2C2035966%2C2036668%2C2036905%2C2036930","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":0.00332,"epssPercentile":0.26541,"ingestedAt":"2026-07-23T20:19:19.293Z","slug":"CVE-2026-8974","body":"## Overview\n\nMemory safety bugs present in Firefox ESR 140.10 and Firefox 150. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. 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":"twilight","depthScore":48,"depthScoreParts":{"impact":48.4,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}