CVE-2026-57962: Vulnerability in Mozilla Thunderbird
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.
AI Analysis
Technical Summary
This vulnerability allows a malicious LDAP server, queried by Thunderbird for address-book autocomplete, to send large amounts of attacker-controlled data that the Thunderbird LDAP client stores until it crashes from memory exhaustion (CWE-400). The issue results in a denial-of-service condition. It affects Thunderbird versions before 140.12.1 and 152.0.1. Mozilla fixed this vulnerability in Thunderbird 140.12.1 and 152.0.1. Exploitation via email is generally not possible due to disabled scripting, but risks remain in browser-like contexts.
Potential Impact
Successful exploitation causes Thunderbird to crash due to memory exhaustion, resulting in denial-of-service. There is no impact on confidentiality or integrity. The CVSS v3.1 base score is 5.3 (medium severity), reflecting network attack vector, high attack complexity, no privileges required, user interaction required, unchanged scope, no confidentiality or integrity impact, and high availability impact.
Mitigation Recommendations
This vulnerability is fixed in Thunderbird versions 140.12.1 and 152.0.1. Users should upgrade to at least these versions to remediate the issue. Since this is not a cloud service, remediation requires updating the client software. No additional mitigation steps are indicated by the vendor advisories.
CVE-2026-57962: Vulnerability in Mozilla Thunderbird
Description
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 v3.1
Score 5.3medium
Affected software
pkg:github/mozilla/thunderbirdRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability allows a malicious LDAP server, queried by Thunderbird for address-book autocomplete, to send large amounts of attacker-controlled data that the Thunderbird LDAP client stores until it crashes from memory exhaustion (CWE-400). The issue results in a denial-of-service condition. It affects Thunderbird versions before 140.12.1 and 152.0.1. Mozilla fixed this vulnerability in Thunderbird 140.12.1 and 152.0.1. Exploitation via email is generally not possible due to disabled scripting, but risks remain in browser-like contexts.
Potential Impact
Successful exploitation causes Thunderbird to crash due to memory exhaustion, resulting in denial-of-service. There is no impact on confidentiality or integrity. The CVSS v3.1 base score is 5.3 (medium severity), reflecting network attack vector, high attack complexity, no privileges required, user interaction required, unchanged scope, no confidentiality or integrity impact, and high availability impact.
Mitigation Recommendations
This vulnerability is fixed in Thunderbird versions 140.12.1 and 152.0.1. Users should upgrade to at least these versions to remediate the issue. Since this is not a cloud service, remediation requires updating the client software. No additional mitigation steps are indicated by the vendor advisories.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-06-26T15:27:32.831Z
- Cvss Version
- null
- State
- PUBLISHED
- Remediation Level
- null
- Vendor Advisory Urls
- [{"url":"https://www.mozilla.org/security/advisories/mfsa2026-62/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-63/","vendor":"Mozilla"}]
Threat ID: 6a446bac27e9c79719c2438a
Added to database: 07/01/2026, 01:21:48 UTC
Last enriched: 07/08/2026, 12:44:17 UTC
Last updated: 08/11/2026, 03:26:41 UTC
Views: 115
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