{"id":"CVE-2025-5272","title":"Memory safety bugs present in Firefox 138 and Thunderbird 138","summary":"Memory safety bugs present in Firefox 138 and Thunderbird 138. 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 vulnerabili…","severity":"high","cvss":7.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L","cwe":["CWE-787"],"vendor":"mozilla","product":"firefox","affected":["firefox < 139.0","thunderbird < 139.0"],"patched":["firefox 139.0","thunderbird 139.0"],"published":"2025-05-27","updated":"2026-09-30","sourceUpdated":"2026-09-30T18:10:00.190","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2025-5272","references":[{"url":"https://bugzilla.mozilla.org/buglist.cgi?bug_id=1726254%2C1742738%2C1960121","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2025-42/","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2025-45/","label":"security@mozilla.org"}],"tags":["nvd"],"epss":0.00326,"epssPercentile":0.23251,"ingestedAt":"2026-09-30T18:17:24.441Z","slug":"CVE-2025-5272","body":"## Overview\n\nMemory safety bugs present in Firefox 138 and Thunderbird 138. 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 139 and Thunderbird 139.\n\n## Affected\n\n- `firefox < 139.0`\n- `thunderbird < 139.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `firefox 139.0`\n- `thunderbird 139.0`","depth":"twilight","depthScore":40,"depthScoreParts":{"impact":40.2,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}