Description
A malicious IMAP server can trigger use-after-free and heap-memory disclosure by sending a crafted ID response. Heap contents can ultimately be persisted to prefs.js. This vulnerability was fixed in Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.
Affected products
mozilla: thunderbird
References4
- www.mozilla.org/security/advisories/mfsa2026-86/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-87/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-88/ Vendor Advisory
- bugzilla.mozilla.org/show_bug.cgi?id=2057805 Permissions Required
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - EPSS — exploit probability
- 0% percentile: 19 · as of 8 November 2026
- CWE
- CWE-416
Could this be exploited in your environment?
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