PT-2026-61868

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 153 Firefox ESR versions prior to 115.38 Firefox ESR versions prior to 140.13 Thunderbird versions prior to 153 Thunderbird version prior to 140.13 Description A use-after-free issue exists in the Disability Access AP...

PT-2026-61891

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 153 Firefox ESR versions prior to 140.13 Thunderbird versions prior to 153 Thunderbird versions prior to 140.13 Description A privilege escalation issue exists within the DOM: Content Processes component...

PT-2026-61908

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 153 Firefox ESR versions prior to 140.13 Thunderbird versions prior to 153 Thunderbird versions prior to 140.13 Description Privilege escalation exists in WebExtensions, allowing an attacker to gain higher levels of...

PT-2026-61866

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 153 Firefox ESR versions prior to 115.38 Firefox ESR versions prior to 140.13 Thunderbird versions prior to 153 Thunderbird version prior to 140.13 Description An information disclosure issue exists within the Graphic...

PT-2026-61870

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 153 Firefox ESR versions prior to 115.38 Firefox ESR versions prior to 140.13 Thunderbird versions prior to 153 Thunderbird version prior to 140.13 Description A site isolation issue exists within the Graphics:...

PT-2026-61881

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 153 Firefox ESR versions prior to 140.13 Thunderbird versions prior to 153 Thunderbird versions prior to 140.13 Description An integer overflow exists in the JavaScript: WebAssembly component. An integer overflow occu...

PT-2026-61871

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 153 Firefox ESR versions prior to 115.38 Firefox ESR versions prior to 140.13 Thunderbird versions prior to 153 Thunderbird version prior to 140.13 Description Incorrect boundary conditions exist within the Audio/Vide...

Security Vulnerabilities fixed in Thunderbird 140.13 — Mozilla

The code to parse MIME headers for display when forwarding a message if the setting to view all headers was enabled had an off-by-one error, allowing a single byte to be read from the memory after the buffer for the headers, and potentially crashing Thunderbird. We are aware that exploit code for...