EUVD-2026-60672

Internally found bugs present in Thunderbird ESR 140.13, Thunderbird ESR 153.0 and Thunderbird 153. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited. This vulnerability was...

CVE-2026-74987

Internally found bugs present in Thunderbird ESR 140.13, Thunderbird ESR 153.0 and Thunderbird 153. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited. This vulnerability was...

CVE-2026-74983 Mitigation bypass in the Data Loss Prevention component

Mitigation bypass in the Data Loss Prevention component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1...

CVE-2026-74987 Internally found bugs fixed in Thunderbird ESR 140.14, Thunderbird ESR 153.1 and Thunderbird 154

Internally found bugs present in Thunderbird ESR 140.13, Thunderbird ESR 153.0 and Thunderbird 153. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited. This vulnerability was...

CVE-2026-74987 Internally found bugs fixed in Thunderbird ESR 140.14, Thunderbird ESR 153.1 and Thunderbird 154

Internally found bugs present in Thunderbird ESR 140.13, Thunderbird ESR 153.0 and Thunderbird 153. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited. This vulnerability was...

CVE-2026-74987

CVE-2026-74987 covers internally discovered bugs in Thunderbird ESR 140.13 , Thunderbird ESR 153.0 , and Thunderbird 153 , with some showing evidence of memory corruption or other security-relevant defects. Mozilla presumes that with sufficient effort some could have been exploited. The CVSS 3.1 ...

CVE-2026-74987

Internally found bugs present in Thunderbird ESR 140.13, Thunderbird ESR 153.0 and Thunderbird 153. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited. This vulnerability was...

CVE-2026-74972

Information disclosure in Firefox/Thunderbird's DOM: Push Subscriptions component exposes sensitive data to malicious sites. CVSS 4.3 (MEDIUM), network-reachable with user interaction required. Fixed in Firefox 154, ESR 140.14/153.1, Thunderbird 154/140.14/153.1. No in-the-wild exploitation repor...

EUVD-2026-60665

Use-after-free in the Layout: Text and Fonts component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1...

EUVD-2026-60668

Race condition, use-after-free in the Graphics component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1...

CVE-2026-74967

Firefox and Thunderbird's Audio/Video: Playback component has a same-origin policy bypass (CVSS 5.4, MEDIUM) exploitable via a crafted page requiring user interaction. Fixed in Firefox 154, Firefox ESR 140.14/153.1, Thunderbird 154, and Thunderbird 140.14/153.1. No in-the-wild exploitation report...

CVE-2026-74963 Same-origin policy bypass in the Networking: Cookies component

Same-origin policy bypass in the Networking: Cookies component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1...

CVE-2026-74967 Same-origin policy bypass in the Audio/Video: Playback component

Same-origin policy bypass in the Audio/Video: Playback component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1...

CVE-2026-74960

CVE-2026-74960 is a site isolation issue in the WebExtensions component of Mozilla Firefox and Thunderbird. The vulnerability allows a web extension to bypass site isolation boundaries, potentially enabling cross-origin data access. It carries a CVSS 3.1 score of 8.1 (HIGH) with a vector of AV:N/...

CVE-2026-74959 Mitigation bypass in the Storage: Cache API component

Mitigation bypass in the Storage: Cache API component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1...

CVE-2026-74953

Firefox's Networking: Cookies component has a privilege escalation flaw. Exploitation requires user interaction (CVSS 8.8 HIGH). Patch available in Firefox 154, ESR 140.14, and ESR 153.1. No in-the-wild exploitation reported; root cause not specified in documents.

EUVD-2026-60755

Privilege escalation due to use-after-free in the Graphics: Canvas2D component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1...

CVE-2026-74946

Privilege escalation due to incorrect boundary conditions in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1...

CVE-2026-74945 Information disclosure in the Graphics: Text component

Information disclosure in the Graphics: Text component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1...

CVE-2026-74942

A privilege escalation flaw in Firefox's Remote Settings Client component allows a remote attacker to gain full system access with no authentication and low complexity. CVSS 8.8 (HIGH). CISA's SSVC rates technical impact as total but confirms no active exploitation. Fixed in Firefox 154, Firefox ...