CVE-2026-74957: Vulnerability in Mozilla Firefox
CVE-2026-74957 is a mitigation bypass vulnerability in the Safe Browsing component of Mozilla Firefox and Thunderbird. This vulnerability was addressed and fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1. The vulnerability has a high severity rating with a CVSS score of 8.1. It allows an attacker to bypass security mitigations, potentially leading to high confidentiality and integrity impacts. No known exploits in the wild have been reported. Users are advised to update to the fixed versions to remediate this issue.
AI Analysis
Technical Summary
CVE-2026-74957 is a mitigation bypass vulnerability affecting the Safe Browsing component in Mozilla Firefox and Thunderbird. The vulnerability allows bypassing of security mitigations, which could compromise confidentiality and integrity. It was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1. The CVSS 3.1 base score is 8.1, indicating high severity with network attack vector, low attack complexity, no privileges required, user interaction required, unchanged scope, and high confidentiality and integrity impacts. The vendor advisory confirms the fix and recommends updating to these versions.
Potential Impact
The vulnerability allows an attacker to bypass mitigation controls in the Safe Browsing component, potentially leading to unauthorized access or manipulation of data, affecting confidentiality and integrity. The CVSS score of 8.1 reflects a high impact. There are no reports of active exploitation in the wild at this time.
Mitigation Recommendations
A fix is available and has been released in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1. Users and administrators should update to these versions or later to remediate the vulnerability. No additional mitigation actions are required beyond applying the official updates.
CVE-2026-74957: Vulnerability in Mozilla Firefox
Description
CVE-2026-74957 is a mitigation bypass vulnerability in the Safe Browsing component of Mozilla Firefox and Thunderbird. This vulnerability was addressed and fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1. The vulnerability has a high severity rating with a CVSS score of 8.1. It allows an attacker to bypass security mitigations, potentially leading to high confidentiality and integrity impacts. No known exploits in the wild have been reported. Users are advised to update to the fixed versions to remediate this issue.
CVSS v3.1
Score 8.1high
Affected software
Mozilla
Firefox
Mozilla
Thunderbird
pkg:github/mozilla/firefox-esrRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-74957 is a mitigation bypass vulnerability affecting the Safe Browsing component in Mozilla Firefox and Thunderbird. The vulnerability allows bypassing of security mitigations, which could compromise confidentiality and integrity. It was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1. The CVSS 3.1 base score is 8.1, indicating high severity with network attack vector, low attack complexity, no privileges required, user interaction required, unchanged scope, and high confidentiality and integrity impacts. The vendor advisory confirms the fix and recommends updating to these versions.
Potential Impact
The vulnerability allows an attacker to bypass mitigation controls in the Safe Browsing component, potentially leading to unauthorized access or manipulation of data, affecting confidentiality and integrity. The CVSS score of 8.1 reflects a high impact. There are no reports of active exploitation in the wild at this time.
Mitigation Recommendations
A fix is available and has been released in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1. Users and administrators should update to these versions or later to remediate the vulnerability. No additional mitigation actions are required beyond applying the official updates.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-08-17T11:58:15.877Z
- State
- PUBLISHED
- Vendor Advisory Urls
- [{"url":"https://www.mozilla.org/security/advisories/mfsa2026-74/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-76/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-77/","vendor":"Mozilla"}]
Threat ID: 6a845507c6e8be03323673e9
Added to database: 08/18/2026, 12:50:15 UTC
Last enriched: 09/11/2026, 22:02:28 UTC
Last updated: 10/02/2026, 03:18:21 UTC
Views: 54
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