Skip to main content

Mozilla Firefox CVE-2026-12302

| EUVDEUVD-2026-37093 MEDIUM
Protection Mechanism Failure (CWE-693)
2026-06-16 mozilla GHSA-hfh9-qj8m-jffj
Authentication Bypass Mozilla
Medium
Disputed · 6.5 Vendor: mozilla
Share

Severity by source

Sources disagree (Medium–Critical)
Vendor (mozilla) PRIMARY
6.5 MEDIUM
AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
vuln.today AI
5.4 MEDIUM

Browser DOM bypass requires victim to navigate to attacker page (UI:R); all other vendor metrics are consistent with the description.

3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
4.0 AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
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 VectorVendor: mozilla

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None

Lifecycle Timeline

3
Analysis Generated
Jul 23, 2026 - 16:45 vuln.today
CVE Published
Jun 16, 2026 - 11:52 cve.org
MEDIUM 6.5
CVE Published
Jun 16, 2026 - 11:52 cve.org
UNKNOWN (no severity yet)

DescriptionCVE.org

Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, and Firefox ESR 115.37.

AnalysisAI

Protection mechanism failure in Mozilla Firefox's DOM Security component permits remote unauthenticated attackers to bypass browser security mitigations, resulting in partial confidentiality and integrity compromise. All Firefox versions prior to 152, Firefox ESR prior to 140.12, and Firefox ESR 115.x prior to 115.37 are affected across major Linux distributions including Red Hat and SUSE. No active exploitation is confirmed (absent from CISA KEV, EPSS at 0.28%), though SSVC classifies the vulnerability as automatable, meaning mass-scale delivery via malvertising or phishing infrastructure is technically feasible if weaponized.

Technical ContextAI

The vulnerability is rooted in CWE-693 (Protection Mechanism Failure), a class where a defensive control exists but can be circumvented rather than directly broken. The affected component - Firefox's DOM Security subsystem - is responsible for enforcing critical browser isolation guarantees such as the Same-Origin Policy, Content Security Policy enforcement, and related DOM-level access controls. A bypass in this layer can allow malicious web content to read or modify data that same-origin restrictions would ordinarily block. The affected product scope is confirmed via CPE cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*, covering all pre-fix Firefox releases. Multiple Mozilla Security Advisory (MFSA) publications (mfsa2026-57 through mfsa2026-61) indicate the fix spans Firefox release, Firefox ESR 140.x, and Firefox ESR 115.x branches, as well as downstream vendor packages for Red Hat and SUSE.

RemediationAI

Upgrade Mozilla Firefox to version 152 or later. For ESR deployments, upgrade to Firefox ESR 140.12 or Firefox ESR 115.37 - vendor-released patches are confirmed available across all three branches via Mozilla advisories MFSA2026-57 through MFSA2026-61 (https://www.mozilla.org/security/advisories/mfsa2026-57/). Enterprise environments running Red Hat or SUSE Linux should apply the corresponding distribution-packaged Firefox updates as they become available through official channels, as both vendors are explicitly tagged in the CVE intelligence. If immediate patching is blocked by change management constraints, consider enforcing strict Content Security Policies at the network proxy or WAF layer to limit what cross-origin content Firefox endpoints are permitted to load; note this is an imperfect compensating control that may break legitimate web applications and does not address the root bypass mechanism. Browser-level enterprise policies restricting navigation to untrusted external domains can also reduce the attack surface with significant usability trade-offs.

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-693 – Protection Mechanism Failure

View all
CVE-2013-2465 CRITICAL POC
9.8
CVE-2024-21412 HIGH POC
8.1
CVE-2013-0431 MEDIUM POC
5.3
CVE-2019-1003030 CRITICAL POC
9.9
CVE-2025-40536 HIGH POC
8.1
CVE-2024-38217 MEDIUM POC
5.4
CVE-2026-21513 HIGH
8.8
CVE-2026-21510 HIGH POC
8.8

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-2022-40684 CRITICAL POC
9.8
CVE-2025-61882 CRITICAL POC
9.8
CVE-2024-0012 CRITICAL POC
9.3
CVE-2023-46805 HIGH POC
8.2

Vendor StatusVendor

SUSE

Severity: Critical
Product Status
openSUSE Tumbleweed Fixed
SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS Affected
SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS Affected
SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS Affected
SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS Affected

Share

CVE-2026-12302 vulnerability details – vuln.today
Back

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