CVE-2026-74938 Mitigation bypass in the JavaScript: GC component

Mitigation bypass in the JavaScript: GC component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1...

CVE-2026-74990 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-2026-75874

A critical (CVSS 10.0) sandbox escape in Firefox and Thunderbird's Remote Settings Client component allows remote, unauthenticated attackers to break out of the application sandbox and achieve full system compromise. No exploitation has been reported, but the flaw affects any Firefox/Thunderbird ...

CVE-2026-74937 Use-after-free in the JavaScript: GC component

Use-after-free in the JavaScript: GC component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1...

CVE-2026-74938 Mitigation bypass in the JavaScript: GC component

Mitigation bypass in the JavaScript: GC component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1...

CVE-2026-75874 Sandbox escape in the Remote Settings Client component

Sandbox escape in the Remote Settings Client component. This vulnerability was fixed in Firefox 154, Thunderbird 154, Firefox ESR 115.40, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 140.15, and Thunderbird 153.2...

CVE-2026-74990

CVE-2026-74990 affects Thunderbird ESR 140.13, ESR 153.0, and Thunderbird 153, where internally found bugs showed evidence of memory corruption or security-relevant defects. Mozilla assesses that, with enough effort, some could have been exploitable, scoring it Critical (CVSS 9.8). The vulnerabil...

CVE-2026-74937

CVE-2026-74937 is a use-after-free vulnerability in the JavaScript: GC component of Mozilla Firefox and Thunderbird . The CVSS 3.1 score is 8.8 (HIGH) with a network attack vector, low complexity, no privileges required, but user interaction required, leading to high impact on confidentiality, in...

CVE-2026-74938

A mitigation bypass in the JavaScript: GC component of Firefox and Thunderbird allows remote attackers to bypass memory-protection mitigations, potentially leading to arbitrary code execution. CVSS 9.1 (CRITICAL). Fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1 . S...

CVE-2026-74976 JIT miscompilation in the JavaScript Engine: JIT component

JIT miscompilation in the JavaScript Engine: JIT 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-2026-74974 Same-origin policy bypass in the Graphics: ImageLib component

Same-origin policy bypass in the Graphics: ImageLib 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-2026-74983

CVE-2026-74983 is a mitigation bypass in the Data Loss Prevention component of Mozilla Firefox and Thunderbird. The vulnerability allows an attacker to circumvent the DLP mechanism, potentially enabling unauthorized data exfiltration. The CVSS v3.1 score is 8.1 (HIGH) with a vector of AV:N/AC:L/P...

CVE-2026-74976

CVE-2026-74976 is a JIT miscompilation in the JavaScript Engine: JIT component of Mozilla Firefox and Thunderbird. The vulnerability can lead to high confidentiality impact (information disclosure) with no integrity or availability impact, per the CVSS 3.1 score of 6.5 (MEDIUM) . Attack requires ...

CVE-2026-74976 JIT miscompilation in the JavaScript Engine: JIT component

JIT miscompilation in the JavaScript Engine: JIT 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

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 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-2026-74974

The vulnerability is a same-origin policy bypass in the Graphics: ImageLib component of Firefox and Thunderbird. Affected versions include Firefox ESR 140.13, ESR 153.0, and Thunderbird ESR 140.13, ESR 153.0. Remediation is to upgrade to Firefox ESR 140.14, ESR 153.1, Thunderbird 140.14, or Thund...

CVE-2026-74974 Same-origin policy bypass in the Graphics: ImageLib component

Same-origin policy bypass in the Graphics: ImageLib 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-2026-74983 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...