PT-2026-61883

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: Navigation component. Recommendations...

PT-2026-61875

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 JIT miscompilation issue exists within the JavaScript: WebAssembly component. JIT...

PT-2026-61921

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 153 Thunderbird versions prior to 153 Description An invalid pointer exists within the Security: PSM component. A pointer is a variable that stores the memory address of another value. Recommendations Update Firefox t...

PT-2026-61910

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 153 Thunderbird versions prior to 153 Description A site isolation issue exists within the Graphics component. Site isolation is a security mechanism that ensures web pages from different sites are processed in separa...

PT-2026-61893

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 same-origin policy bypass exists in the Networking: DNS component. The same-origin policy i...

PT-2026-61896

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 153 Thunderbird versions prior to 153 Description Information disclosure occurs due to uninitialized memory within the Graphics: WebGPU component. Uninitialized memory refers to a condition where a program uses a memo...

PT-2026-61886

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 information disclosure issue exists within the Framework component of DevTools...

PT-2026-61903

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 information disclosure issue exists within the Storage: IndexedDB component. IndexedDB is ...

PT-2026-61906

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 153 Thunderbird versions prior to 153 Description A mitigation bypass exists within the DOM Security component. The Document Object Model DOM is a programming interface for web documents that represents the page so th...

PT-2026-61900

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 153 Thunderbird versions prior to 153 Description A sandbox escape exists within the DOM networking component. A sandbox is a security mechanism used to isolate running applications from the rest of the system to...

PT-2026-61916

Name of the Vulnerable Software and Affected Versions Firefox for Android versions prior to 153 Description A spoofing issue exists in Firefox for Android, which could allow an attacker to deceive users by impersonating a legitimate site or entity. Recommendations Update to version 153...

PT-2026-61913

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 153 Thunderbird versions prior to 153 Description A privilege escalation issue exists within the Data Loss Prevention component. Recommendations Update Firefox to version 153. Update Thunderbird to version 153...

PT-2026-61915

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 153 Thunderbird versions prior to 153 Description A spoofing issue exists within the Address Bar component, which could allow an attacker to deceive users by manipulating the displayed address. Recommendations Update...

PT-2026-61901

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 153 Thunderbird versions prior to 153 Description An integer overflow occurs in the Libraries component of NSS due to incorrect boundary conditions. An integer overflow is a condition where an arithmetic operation...

PT-2026-61888

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 153 Thunderbird versions prior to 153 Description A denial-of-service issue exists within the Graphics: WebGPU component. WebGPU is a modern API that allows web applications to access the GPU for hardware-accelerated...

PT-2026-61895

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 mitigation bypass exists within the DOM: Networking component. Recommendations Update Firef...

PT-2026-61914

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 153 Thunderbird versions prior to 153 Description An integer overflow exists within the Graphics: ImageLib component. An integer overflow occurs when an arithmetic operation attempts to create a numeric value that...

PT-2026-61918

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 153 Thunderbird versions prior to 153 Description A mitigation bypass exists within the Networking component. Recommendations Update Firefox to version 153. Update Thunderbird to version 153...

Security Vulnerabilities fixed in Thunderbird 153 — 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. Memory safety bugs present in...

PT-2026-61922

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 153 Thunderbird versions prior to 153 Description A JIT miscompilation issue exists within the JIT component of the JavaScript Engine. JIT Just-In-Time compilation is a method used by the engine to improve performance...