Out-of-bounds read in Mozilla Thunderbird - CVE-2026-4371
Published: March 25, 2026
Vulnerability identifier: #VU124597
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-4371
CWE-ID: CWE-125
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 gain access to potentially sensitive information.
The vulnerability exists due to a boundary condition when reading responses from the IMAP server. A remote attacker with control over a malicious IMAP server can send specially crafted responses to the email client, trigger an out-of-bounds read error and read contents of memory on the system.
How to mitigate CVE-2026-4371
Install updates from vendor's website.