RHSA-2026:8289 Red Hat Security Advisory: thunderbird security update
thunderbird: Spoofing issue in Thunderbird thunderbird: Out of bounds read in IMAP parsing firefox: thunderbird: Race condition, use-after-free in the Graphics: WebRender component firefox: thunderbird: Incorrect boundary conditions in the Graphics: Canvas2D component firefox: thunderbird: Incorrect boundary conditions in the Graphics: Canvas2D component firefox: thunderbird: Sandbox escape due to incorrect boundary conditions in the Telemetry component firefox: thunderbird: Sandbox escape due to use-after-free in the Disability Access APIs component firefox: thunderbird: Sandbox escape due to incorrect boundary conditions, integer overflow in the XPCOM component firefox: thunderbird: Sandbox escape due to incorrect boundary conditions, integer overflow in the XPCOM component firefox: thunderbird: Use-after-free in the CSS Parsing and Computation component firefox: thunderbird: Sandbox escape in the Responsive Design Mode component firefox: thunderbird: Incorrect boundary conditions in the Audio/Video: Playback component firefox: thunderbird: Incorrect boundary conditions, integer overflow in the Graphics component firefox: thunderbird: Incorrect boundary conditions in the Audio/Video: Web Codecs component firefox: thunderbird: Use-after-free in the Layout: Text and Fonts component firefox: thunderbird: Incorrect boundary conditions in the Audio/Video: Web Codecs component firefox: thunderbird: JIT miscompilation in the JavaScript Engine: JIT component firefox: thunderbird: Incorrect boundary conditions in the Layout: Text and Fonts component firefox: thunderbird: Mitigation bypass in the Networking: HTTP component firefox: thunderbird: Use-after-free in the JavaScript Engine component firefox: thunderbird: JIT miscompilation in the JavaScript Engine component firefox: thunderbird: Denial-of-service in the WebRTC: Signaling component firefox: thunderbird: Undefined behavior in the WebRTC: Signaling component firefox: thunderbird: Incorrect boundary conditions in the Graphics: Canvas2D component firefox: thunderbird: Incorrect boundary conditions in the Graphics: Canvas2D component firefox: thunderbird: Incorrect boundary conditions in the Graphics component firefox: thunderbird: Incorrect boundary conditions in the Audio/Video: GMP component firefox: thunderbird: Incorrect boundary conditions in the Audio/Video component firefox: thunderbird: Use-after-free in the Widget: Cocoa component firefox: thunderbird: Information disclosure in the Widget: Cocoa component firefox: thunderbird: Incorrect boundary conditions in the Graphics component firefox: thunderbird: Incorrect boundary conditions in the Audio/Video component firefox: thunderbird: Uninitialized memory in the Graphics: Canvas2D component firefox: thunderbird: Incorrect boundary conditions, uninitialized memory in the JavaScript Engine component firefox: thunderbird: Privilege escalation in the Netmonitor component firefox: thunderbird: Undefined behavior in the WebRTC: Signaling component firefox: thunderbird: Incorrect boundary conditions in the Graphics: Text component firefox: thunderbird: Memory safety bugs fixed in Firefox ESR 140.9, Thunderbird ESR 140.9, Firefox 149 and Thunderbird 149 firefox: thunderbird: Memory safety bugs fixed in Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird ESR 140.9, Firefox 149 and Thunderbird 149
CVSS v3.1 score: 7.5