Uncontrolled Memory Allocation in Mozilla Thunderbird - CVE-2026-57962
Published: July 22, 2026
Vulnerability identifier: #VU139184
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-57962
CWE-ID: CWE-789
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Mozilla
Affected software:
Mozilla Thunderbird
Mozilla Thunderbird
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to uncontrolled memory allocation in the Thunderbird LDAP client when querying a malicious LDAP address-book server for autocomplete. A remote attacker can return arbitrarily large amounts of attacker-supplied data to cause a denial of service.
How to mitigate CVE-2026-57962
Install security update from vendor's website.