{"id":"CVE-2026-110247","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-110247","generatedAt":"2026-10-28T02:57:55.897Z","title":"Several buffer-growth sites in libmime performed size arithmetic in 32-bit types without overflow checks.","description":"Several buffer-growth sites in libmime performed size arithmetic in 32-bit types without overflow checks. On a sufficiently large message the growth guard could fail open, or the buffer could be reallocated smaller than required, and a subsequent memcpy would then write attacker-controlled data across adjacent heap allocations. This vulnerability was fixed in Thunderbird 158 and Thunderbird 153.6.","published":"2026-10-13T19:18:49.000Z","lastModified":"2026-10-27T19:17:10.000Z","status":"Awaiting Analysis","sourceIdentifier":"security@mozilla.org","cvss":{"version":"3.1","score":8.4,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-190"],"affected":[],"epss":{"score":0.00173,"percentile":0.06714,"date":"2026-10-26","history":[{"date":"2026-10-14","score":0.00171,"percentile":0.06078}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.17%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"scored","label":"Newly scored","at":"2026-10-20T19:15:07.000Z","detail":{"from":null,"score":"8.4","severity":"HIGH","fromSeverity":null},"summary":"Now scored CVSS 8.4 HIGH."},{"kind":"new","label":"New CVE","at":"2026-10-13T19:18:49.000Z","detail":{"score":null,"severity":null,"publishedAt":"2026-10-13T19:18:49.493Z"},"summary":"New CVE, high severity (CVSS 8.4)."}],"references":[{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=2071621","source":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-109/","source":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-122/","source":"security@mozilla.org"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-110247","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}