A malicious LDAP server, which a Thunderbird user is configured to query for address-book autocomplete, can stash arbitrarily large amounts of attacker-supplied data into the Thunderbird LDAP client until it crashes due to memory exhaustion. This vulnerability was fixed in Thunderbird 152.0.1 and Thunderbird 140.12.1.
Fix
Patch, vendor advisory and mitigation references on NVD 2
- https://www.mozilla.org/security/advisories/mfsa2026-63/ Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-64/ Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 5.3 · mozillaNVD modified 2026-10-25 17:10
Affected (CPE criteria) 2
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:*cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:*
References 3
- https://bugzilla.mozilla.org/show_bug.cgi?id=2042872 Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2026-63/ Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-64/ Vendor Advisory