CVE-2026-74986

A site isolation flaw in Firefox/Thunderbird's CSS Parsing and Computation component allows cross-origin data leakage. NVD rates it CVSS 9.1 (network, no auth). No active exploitation confirmed; patch in Firefox 154, ESR 153.1, Thunderbird 154, and 153.1. Update affected browsers immediately.

CVE-2026-74988

CVE-2026-74988 covers internally found bugs in Thunderbird ESR 153.0 , Thunderbird 153 , Firefox ESR 153.0 , and Firefox 153 . Some of these bugs showed evidence of memory corruption or another security-relevant defect, and Mozilla presumes that with enough effort some could have been exploited. ...

CVE-2026-74988 Internally found bugs fixed in Thunderbird ESR 153.1 and Thunderbird 154

Internally found bugs present in 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 fixed in Firefox 154,...

CVE-2026-74984 Race condition in the JavaScript Engine component

Race condition in the JavaScript Engine component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1...

CVE-2026-74982 Denial-of-service in the Widget component

Denial-of-service in the Widget component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1...

CVE-2026-74984 Race condition in the JavaScript Engine component

Race condition in the JavaScript Engine component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1...

CVE-2026-74982

CVE-2026-74982 is a denial-of-service vulnerability in the Widget component of Firefox and Thunderbird . The CVSS 3.1 score is 7.5 (High) , with a network attack vector requiring no privileges or user interaction, resulting in high availability impact. CISA's SSVC assessment indicates no known ex...

CVE-2026-74980 Clickjacking issue in the Downloads component in Firefox for Android

Clickjacking issue in the Downloads component in Firefox for Android. This vulnerability was fixed in Firefox 154...

CVE-2026-74980 Clickjacking issue in the Downloads component in Firefox for Android

Clickjacking issue in the Downloads component in Firefox for Android. This vulnerability was fixed in Firefox 154...

CVE-2026-74984

A race condition in the Firefox/Thunderbird JavaScript Engine allows remote attackers (with user interaction) to achieve high confidentiality and integrity impact. CISA reports no exploitation. Remediation: upgrade to Firefox 154, Firefox ESR 153.1, Thunderbird 154, or Thunderbird 153.1.

CVE-2026-74980

A clickjacking flaw in Firefox for Android's Downloads component allows a malicious page to trick users into unintended downloads. CVSS 6.5 (MEDIUM), network-accessible with user interaction. Fixed in Firefox 154; the Nessus plugin confirms no in-the-wild exploitation is known.

CVE-2026-74982 Denial-of-service in the Widget component

Denial-of-service in the Widget component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1...

CVE-2026-74981 Site isolation issue in the Audio/Video: Web Codecs component

Site isolation issue in the Audio/Video: Web Codecs component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1...

CVE-2026-74981 Site isolation issue in the Audio/Video: Web Codecs component

Site isolation issue in the Audio/Video: Web Codecs component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1...

CVE-2026-74981

Mozilla Firefox and Thunderbird are vulnerable to a site isolation bypass in the Audio/Video: Web Codecs component, allowing cross-origin data access (CVSS 8.1, HIGH). Exploitation requires user interaction; no in-the-wild exploitation is reported. Remediation: upgrade to Firefox 154/ESR 153.1 or...

CVE-2026-74978 Clickjacking issue in the Widget component

Clickjacking issue in the Widget component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1...

CVE-2026-74975 Spoofing issue in the Downloads component in Firefox for Android

Spoofing issue in the Downloads component in Firefox for Android. This vulnerability was fixed in Firefox 154...

CVE-2026-74978 Clickjacking issue in the Widget component

Clickjacking issue in the Widget component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1...

CVE-2026-74977 Integer overflow in the Graphics component

Integer overflow in the Graphics component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1...

CVE-2026-74979 Mitigation bypass in the Add-ons Manager component

Mitigation bypass in the Add-ons Manager component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1...