{"id":"CVE-2026-92238","title":"A maliciously constructed mail header could lead to multiple fields being parsed as one, or potential memory safety violations","summary":"A maliciously constructed mail header could lead to multiple fields being parsed as one, or potential memory safety violations. This vulnerability was fixed in Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.","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-444","CWE-843"],"vendor":"mozilla","product":"thunderbird","affected":["thunderbird < 140.16.0","thunderbird >= 141.0, < 153.3.0","thunderbird >= 154.0, < 156.0"],"patched":["thunderbird 156.0"],"published":"2026-09-15","updated":"2026-09-24","sourceUpdated":"2026-09-24T14:15:49.947","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-92238","references":[{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=2060601","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-94/","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-95/","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-96/","label":"security@mozilla.org"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-92238.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-92238"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2534199"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-92238"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-92238"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-95/#CVE-2026-92238"},{"url":"https://access.redhat.com/errata/RHSA-2026:70642"},{"url":"https://access.redhat.com/errata/RHSA-2026:73130"},{"url":"https://access.redhat.com/errata/RHSA-2026:73971"}],"tags":["nvd","cve.org","csaf","vex","red-hat","score-dispute"],"epss":0.00539,"epssPercentile":0.45155,"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"total","timestamp":"2026-09-22T18:43:18.822790Z"},"scores":{"nvd":9.8,"vendor":6.1,"adp":9.8},"ingestedAt":"2026-09-15T20:44:02.608Z","slug":"CVE-2026-92238","body":"## Overview\n\nA maliciously constructed mail header could lead to multiple fields being parsed as one, or potential memory safety violations. This vulnerability was fixed in Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.\n\n## Affected\n\n- `thunderbird < 140.16.0`\n- `thunderbird >= 141.0, < 153.3.0`\n- `thunderbird >= 154.0, < 156.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `thunderbird 156.0`\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 10 · updated 2026-09-30 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-92238.json)\n- **RHSA-2026:70642** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9) · released 2026-09-24 · [advisory](https://access.redhat.com/errata/RHSA-2026:70642)\n- **RHSA-2026:73130** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10) · released 2026-09-29 · [advisory](https://access.redhat.com/errata/RHSA-2026:73130)\n- **RHSA-2026:73971** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 8) · released 2026-09-30 · [advisory](https://access.redhat.com/errata/RHSA-2026:73971)","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":209357,"id":"CVE-2026-92238","ts":1790107868856,"field":"cvss","old":"6.1","new":"9.8"},{"seq":209356,"id":"CVE-2026-92238","ts":1790107868856,"field":"severity","old":"medium","new":"critical"},{"seq":206381,"id":"CVE-2026-92238","ts":1789663223896,"field":"cvss","old":null,"new":"6.1"},{"seq":206380,"id":"CVE-2026-92238","ts":1789663223896,"field":"severity","old":"none","new":"medium"}]}