Skip to main content

Mozilla Firefox CVE-2026-6771

| EUVDEUVD-2026-24112 CRITICAL
Authentication Bypass Using an Alternate Path or Channel (CWE-288)
2026-04-21 mozilla GHSA-88fc-5m2g-g6q2
Authentication Bypass Mozilla Red Hat Suse
Critical
Disputed · 9.8 NVD
Share

Severity by source

Sources disagree (Medium–Critical)
NVD PRIMARY
9.8 CRITICAL
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
SUSE
CRITICAL
qualitative
Red Hat
6.1 MEDIUM
qualitative

vuln.today treats the vendor’s rating as authoritative. A higher third-party CVSS (e.g. CISA-ADP) is shown for transparency but does not drive the headline severity.

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Lifecycle Timeline

8
Patch released
Apr 29, 2026 - 02:30 nvd
Patch available
Analysis Updated
Apr 22, 2026 - 00:27 vuln.today
v2 (cvss_changed)
Re-analysis Queued
Apr 22, 2026 - 00:22 vuln.today
cvss_changed
Analysis Generated
Apr 21, 2026 - 20:25 vuln.today
CVSS changed
Apr 21, 2026 - 20:22 NVD
9.8 (CRITICAL)
EUVD ID Assigned
Apr 21, 2026 - 13:15 euvd
EUVD-2026-24112
Analysis Generated
Apr 21, 2026 - 13:15 vuln.today
CVE Published
Apr 21, 2026 - 12:41 nvd
CRITICAL 9.8

DescriptionCVE.org

Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 150 and Firefox ESR 140.10.

AnalysisAI

DOM security mitigation bypass in Mozilla Firefox allows remote unauthenticated attackers to completely compromise browser security, achieving high confidentiality, integrity, and availability impact. Affects Firefox versions prior to 150 and Firefox ESR versions prior to 140.10. The vulnerability bypasses critical browser security controls designed to protect the Document Object Model. SSVC assessment indicates the flaw is automatable with total technical impact, though no active exploitation has been confirmed at time of analysis. CVSS 9.8 critical rating reflects network-based attack with no complexity barriers.

Technical ContextAI

The vulnerability resides in Firefox's DOM Security component, which enforces security boundaries between web content and browser internals. CWE-288 (Authentication Bypass Using an Alternate Path or Channel) indicates attackers can circumvent authentication or authorization checks through an unintended code path. The DOM security layer normally prevents malicious web content from accessing privileged browser APIs, reading cross-origin data, or executing code outside sandboxed contexts. This mitigation bypass suggests flaws in Same-Origin Policy enforcement, Content Security Policy validation, or privilege separation mechanisms. Affected products per CPE data include all Mozilla Firefox releases prior to version 150 and all Firefox ESR (Extended Support Release) versions prior to 140.10, spanning both consumer and enterprise deployment channels.

RemediationAI

Vendor-released patches: Firefox 150 and Firefox ESR 140.10 contain complete fixes for this vulnerability. Organizations should immediately upgrade all Firefox installations to version 150 or later, and all Firefox ESR deployments to version 140.10 or later. Enterprise environments using Firefox ESR for stability should prioritize the ESR 140.10 update through existing patch management workflows. Download patched versions from official Mozilla channels at mozilla.org or through operating system package managers. Consult Mozilla Security Advisories MFSA2026-30, MFSA2026-32, MFSA2026-33, and MFSA2026-34 for additional context and deployment guidance. If immediate patching is infeasible, temporary risk reduction measures include restricting Firefox usage to trusted internal sites only (disable internet browsing), deploying Firefox in isolated virtual desktop environments to contain potential compromise, or temporarily switching to alternative browsers until patching completes. Note these workarounds provide only partial mitigation given the AV:N/AC:L/PR:N/UI:N attack profile, and patching remains the only complete remediation.

More in Mozilla

View all
CVE-2015-4495 HIGH POC
8.8 Aug 08

The PDF reader in Mozilla Firefox before 39.0.3, Firefox ESR 38.x before 38.1.1, and Firefox OS before 2.2 allows remote
CVE-2013-1690 HIGH POC
8.8 Jun 26

Mozilla Firefox before 22.0, Firefox ESR 17.x before 17.0.7, Thunderbird before 17.0.7, and Thunderbird ESR 17.x before

CVE-2013-0758 CRITICAL POC
9.3 Jan 13

Mozilla Firefox before 18.0, Firefox ESR 10.x before 10.0.12 and 17.x before 17.0.2, Thunderbird before 17.0.2, Thunderb
CVE-2013-0753 CRITICAL POC
9.3 Jan 13

Use-after-free vulnerability in the serializeToStream implementation in the XMLSerializer component in Mozilla Firefox b
CVE-2012-3993 CRITICAL POC
9.3 Oct 10

The Chrome Object Wrapper (COW) implementation in Mozilla Firefox before 16.0, Firefox ESR 10.x before 10.0.8, Thunderbi
CVE-2013-1710 CRITICAL POC
10.0 Aug 07

The crypto.generateCRMFRequest function in Mozilla Firefox before 23.0, Firefox ESR 17.x before 17.0.8, Thunderbird befo
CVE-2017-3823 HIGH POC
8.8 Feb 01

An issue was discovered in the Cisco WebEx Extension before 1.0.7 on Google Chrome, the ActiveTouch General Plugin Conta
CVE-2014-8636 HIGH POC
7.5 Jan 14

The XrayWrapper implementation in Mozilla Firefox before 35.0 and SeaMonkey before 2.32 does not properly interact with

CVE-2013-0757 CRITICAL POC
9.3 Jan 13

The Chrome Object Wrapper (COW) implementation in Mozilla Firefox before 18.0, Firefox ESR 17.x before 17.0.2, Thunderbi
CVE-2014-1510 CRITICAL POC
9.8 Mar 19

The Web IDL implementation in Mozilla Firefox before 28.0, Firefox ESR 24.x before 24.4, Thunderbird before 24.4, and Se
CVE-2014-1511 CRITICAL POC
9.8 Mar 19

Mozilla Firefox before 28.0, Firefox ESR 24.x before 24.4, Thunderbird before 24.4, and SeaMonkey before 2.25 allow remo
CVE-2013-0643 HIGH
8.8 Feb 27

The Firefox sandbox in Adobe Flash Player before 10.3.183.67 and 11.x before 11.6.602.171 on Windows and Mac OS X, and b

Same weakness CWE-288 – Authentication Bypass Using an Alternate Path or Channel

View all
CVE-2024-1709 CRITICAL POC
10.0
CVE-2020-10148 CRITICAL POC
9.8
CVE-2024-55591 CRITICAL POC
9.8
CVE-2025-2747 CRITICAL POC
9.8
CVE-2025-2746 CRITICAL POC
9.8
CVE-2025-4427 MEDIUM POC
5.3
CVE-2025-34026 CRITICAL POC
9.2
CVE-2026-23760 CRITICAL POC
9.8

Same technique Authentication Bypass

View all
CVE-2023-22515 CRITICAL POC
9.8
CVE-2012-4681 CRITICAL POC
9.8
CVE-2013-2465 CRITICAL POC
9.8
CVE-2011-3544 CRITICAL POC
9.8
CVE-2012-1723 CRITICAL POC
9.8
CVE-2017-10271 HIGH POC
7.5
CVE-2015-1427 CRITICAL POC
9.8
CVE-2025-3248 CRITICAL POC
9.8

Vendor StatusVendor

SUSE

Severity: Critical
Product Status
SUSE Liberty Linux 10 Fixed
SUSE Liberty Linux 8 Fixed
SUSE Liberty Linux 9 Fixed
SUSE Linux Enterprise Server 16.0 SUSE Linux Enterprise Server for SAP applications 16.0 Fixed
openSUSE Leap 16.0 Fixed

Share

CVE-2026-6771 vulnerability details – vuln.today
Back

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy