Medium 5.3Published Jun 30, 2026

CVE-2026-57962Denial-of-service via malicious LDAP address-book server

Updated under an hour ago (Oct 26, 2026, 10:40 PM ET)

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It affects Mozilla Thunderbird. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

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.

CVSS: 5.3 MEDIUM (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H
Weakness (CWE): CWE-400
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: mozilla
NVD analysis: Analyzed
Record last updated: Jul 1, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Mozilla Thunderbird mozilla:thunderbird (from the name)	140.12.1 builds before 140.* not affected; from 152.0.1 not affected	CNA record
mozilla thunderbird mozilla:thunderbird	before 140.12.1; before 152.0.1	NVD

References

References

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

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.