CVE-2026-8962: Vulnerability in Mozilla Firefox
CVE-2026-8962 is a mitigation bypass vulnerability in the DOM security component of Mozilla Firefox. It was addressed in Firefox 151 and Firefox ESR 140.11. The vulnerability has a high severity with a CVSS score of 8.1, indicating it could lead to significant confidentiality and integrity impacts. Mozilla has released official fixes for this and related vulnerabilities in these Firefox versions. There are no known exploits in the wild at this time. Users are advised to update to the fixed versions to mitigate the risk.
AI Analysis
Technical Summary
CVE-2026-8962 is a high-severity mitigation bypass vulnerability affecting the DOM security component in Mozilla Firefox. This vulnerability allows bypassing certain security mitigations, potentially compromising browser security. It was fixed in Firefox 151 and Firefox ESR 140.11 as part of a broader security update addressing multiple vulnerabilities. The CVSS 3.1 vector (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N) indicates network attack vector, low attack complexity, no privileges required, user interaction required, unchanged scope, and high confidentiality and integrity impacts with no availability impact. The vendor advisories confirm the availability of official patches in these Firefox releases.
Potential Impact
Successful exploitation of this vulnerability could allow an attacker to bypass security mitigations in the DOM component, potentially leading to high confidentiality and integrity impacts such as unauthorized access to sensitive information or manipulation of browser behavior. However, no active exploits have been reported in the wild. The vulnerability affects Firefox and Thunderbird products prior to the fixed versions.
Mitigation Recommendations
Mozilla has released official fixes for CVE-2026-8962 in Firefox 151 and Firefox ESR 140.11. Users and administrators should update to these versions or later to remediate this vulnerability. No additional mitigation actions are required beyond applying the official patches.
CVE-2026-8962: Vulnerability in Mozilla Firefox
Description
CVE-2026-8962 is a mitigation bypass vulnerability in the DOM security component of Mozilla Firefox. It was addressed in Firefox 151 and Firefox ESR 140.11. The vulnerability has a high severity with a CVSS score of 8.1, indicating it could lead to significant confidentiality and integrity impacts. Mozilla has released official fixes for this and related vulnerabilities in these Firefox versions. There are no known exploits in the wild at this time. Users are advised to update to the fixed versions to mitigate the risk.
CVSS v3.1
Score 8.1high
Affected software
Run 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-2026-8962 is a high-severity mitigation bypass vulnerability affecting the DOM security component in Mozilla Firefox. This vulnerability allows bypassing certain security mitigations, potentially compromising browser security. It was fixed in Firefox 151 and Firefox ESR 140.11 as part of a broader security update addressing multiple vulnerabilities. The CVSS 3.1 vector (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N) indicates network attack vector, low attack complexity, no privileges required, user interaction required, unchanged scope, and high confidentiality and integrity impacts with no availability impact. The vendor advisories confirm the availability of official patches in these Firefox releases.
Potential Impact
Successful exploitation of this vulnerability could allow an attacker to bypass security mitigations in the DOM component, potentially leading to high confidentiality and integrity impacts such as unauthorized access to sensitive information or manipulation of browser behavior. However, no active exploits have been reported in the wild. The vulnerability affects Firefox and Thunderbird products prior to the fixed versions.
Mitigation Recommendations
Mozilla has released official fixes for CVE-2026-8962 in Firefox 151 and Firefox ESR 140.11. Users and administrators should update to these versions or later to remediate this vulnerability. No additional mitigation actions are required beyond applying the official patches.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-05-19T12:29:59.235Z
- Cvss Version
- null
- State
- PUBLISHED
- Remediation Level
- null
- Vendor Advisory Urls
- [{"url":"https://www.mozilla.org/security/advisories/mfsa2026-46/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-48/","vendor":"Mozilla"}]
Threat ID: 6a0c677fec166c07b0a997f7
Added to database: 05/19/2026, 13:37:03 UTC
Last enriched: 05/26/2026, 20:41:41 UTC
Last updated: 07/31/2026, 19:23:00 UTC
Views: 86
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.