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Red Hat EUVDEUVD-2026-14839

| CVE-2026-4712 HIGH
Information Exposure (CWE-200)
2026-03-24 mozilla GHSA-vcpc-fv28-ppg5
Information Disclosure Red Hat Mozilla Suse
7.5
CVSS 3.1 · NVD
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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Send malicious network request to Firefox browser
  2. Exploit
    Exploit Widget: Cocoa component vulnerability
  3. Execution
    Access sensitive memory contents without authentication
  4. Impact
    Disclose confidential user information

Vulnerability Assessment

Weakness
CWE
CWE-200
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V14 - Data Protection Data exposure prevention
MITRE ATT&CK

2 techniques across 2 tactics: Collection, Discovery

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

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Exploitation Conditions

Remote unauthenticated attacker exploits vulnerability in Firefox's Cocoa widget component. Affects Firefox versions below 149 and Firefox ESR below 140.9. No user interaction required. Vulnerable on macOS systems using affected Firefox versions with default configuration.
Impact

Without CVSS vector data and EPSS scores, risk assessment relies on Mozilla's classification as a security advisory (MFSA2026-20 and MFSA2026-22) and the information disclosure categorization. Information disclosure vulnerabilities typically present moderate to high risk depending on sensitivity of exposed data and attack complexity. The vulnerability's presence in the Cocoa widget layer—a fundamental UI component—suggests potential for widespread impact across Firefox macOS users. The absence of actively disclosed POC or KEV status indicates this may be a coordinated disclosure without current active exploitation. However, the dual advisory references and specific version targeting suggest Mozilla treated this with sufficient severity to warrant ESR updates, indicating real-world risk justifying prompt patching. This appears to be a legitimate security priority rather than inflated severity, as information leakage from core UI components can enable follow-on attacks or credential exposure.
Exploit ScenarioDerived

An attacker could craft a malicious webpage or interact with a vulnerable Firefox instance on macOS to trigger information disclosure through the Cocoa widget component, potentially exposing sensitive data such as clipboard contents, cached credentials, or internal browser state that would normally be protected. Since this is a local or same-machine attack vector facilitated through the widget layer, exploitation would likely require the user to visit a malicious website or interact with a compromised browser extension, after which the Cocoa component's information disclosure flaw would leak data accessible to the attacker's script or extension code. No public POC is currently indicated in available intelligence, suggesting Mozilla coordinated this disclosure to patch before widespread awareness.
This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).
Patch available 0.0% exploitation probability (EPSS)

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AnalysisAIv1 – Mar 24, 2026

An information disclosure vulnerability exists in the Widget: Cocoa component of Mozilla Firefox and Firefox ESR, allowing attackers to access sensitive information through the affected rendering engine. Firefox versions prior to 149 and Firefox ESR versions prior to 140.9 are vulnerable. The vulnerability permits unauthorized information leakage, though the specific attack mechanism and data exposure scope require analysis of the referenced Mozilla security advisories.

RemediationAI

Users must upgrade Firefox to version 149 or later immediately, and Firefox ESR users must upgrade to version 140.9 or later. Visit https://www.mozilla.org/security/advisories/mfsa2026-20/ and https://www.mozilla.org/security/advisories/mfsa2026-22/ for detailed advisory information and download links. For organizations unable to immediately patch, implement network segmentation to restrict Firefox's access to sensitive resources, disable browser-based access to high-value systems until patching is complete, and consider temporary deployment of alternative browsers for critical tasks. Enable automatic Firefox updates if not already configured to ensure rapid deployment of patch versions once upgraded, and monitor systems for any evidence of exploitation related to Cocoa widget information disclosure as noted in the Mozilla security advisories.

Affected VersionsENISA

Firefox ESR unspecified <140.9
Firefox unspecified <149

Affected Packages

euvd firefox_esr_unspecified fix: 140.9
euvd firefox_unspecified fix: 149

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 2 packages in euvd

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Technical ContextAI · show details

The vulnerability resides in the Widget: Cocoa component, which is the native macOS widget abstraction layer in Firefox responsible for rendering graphical user interface elements and managing system-level interactions on Apple's Cocoa framework. The Cocoa widget backend provides critical bindings between Firefox's cross-platform UI code and native macOS APIs. This vulnerability represents an information disclosure weakness (CWE category unspecified in available data) within this native integration layer, suggesting improper handling of sensitive data during widget rendering, event processing, or system resource interaction on macOS systems. Affected products include Mozilla Firefox (cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*) and Firefox ESR (cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:*) across all architectures and configurations prior to specified patch versions.

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  • Exploit and PoC references, threat intelligence from 22 sources
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Severity by source

NVD PRIMARY 7.5 HIGH
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
SUSE HIGH
Red Hat 6.5 MEDIUM

Primary rating from NVD.

CVSS VectorNVD

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

Lifecycle Timeline

2
Patch released
Mar 31, 2026 - 21:13 nvd
Patch available
CVE Published
Mar 24, 2026 - 12:30 nvd
HIGH 7.5

DescriptionCVE.org

Information disclosure in the Widget: Cocoa component. This vulnerability affects Firefox < 149 and Firefox ESR < 140.9.

Executive ViewAI

Why It Matters

CVE-2026-4712 presents notable security risk, a information exposure vulnerability rated CVSS 7.5. This could expose sensitive information including credentials, configuration data, or user records to unauthorized parties. Organizations should apply vendor updates when available and consider compensating controls in the interim.

Business Impact: High
Compensating Controls

Apply vendor patch. If immediate patching is not feasible: (1) Restrict access to affected endpoints; (2) Implement additional authorization checks; (3) Enable audit logging.

Threat Intelligence Overview

EPSS Score
0.0%
Top 98% exploitable
Data Quality
6 sources
Confidence: High
EUVD NVD CVE.org EPSS Vulnrichment Vendor VulDB

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity HIGH
CISA KEV No
Public POC No
EPSS 0.0%
Patch available Yes
Active threat No
Deciding rule
HIGH severity (CVSS 7.0-8.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision
Scheduled
Exploitation
None
System Exposure· derived
Open
Automatable
Yes
Human Impact
High
Technical Impact
Partial

Priority Score

38
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +38
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Information Disclosure MEDIUM

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.

Related Vulnerabilities in Firefox Multiple Memory and Boundary Vulnerabilities

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CVE-2026-4720 CRITICAL
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CVE-2026-4713 HIGH
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CVE-2026-4729 CRITICAL
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CVE-2026-4701 CRITICAL
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CVE-2026-4702 CRITICAL
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CVE-2026-4704 HIGH
7.5
CVE-2026-4706 HIGH
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CVE-2026-4707 HIGH
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CVE-2026-4709 HIGH
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CVE-2026-4710 CRITICAL
9.8
CVE-2026-4711 CRITICAL
9.8
CVE-2026-4723 CRITICAL
9.8

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Same weakness CWE-200 – Information Exposure

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6.5
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5.3
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CVE-2017-16894 HIGH POC
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Same technique Information Disclosure

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CVE-2013-2251 CRITICAL POC
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Vendor StatusVendor

Debian

firefox
Release Status Fixed Version Urgency
sid vulnerable 148.0.2-1 -
(unstable) fixed (unfixed) -
firefox-esr
Release Status Fixed Version Urgency
bullseye vulnerable 115.14.0esr-1~deb11u1 -
bullseye (security) vulnerable 140.8.0esr-1~deb11u1 -
bookworm vulnerable 128.14.0esr-1~deb12u1 -
bookworm (security) vulnerable 140.8.0esr-1~deb12u1 -
trixie (security), trixie vulnerable 140.8.0esr-1~deb13u1 -
forky, sid vulnerable 140.8.0esr-1 -
(unstable) fixed (unfixed) -

SUSE

Severity: High
Product Status
Image SLES15-SP5-SAP-Azure-LI-BYOS Image SLES15-SP5-SAP-Azure-LI-BYOS-Production Image SLES15-SP5-SAP-Azure-VLI-BYOS Image SLES15-SP5-SAP-Azure-VLI-BYOS-Production Image SLES15-SP6-SAP-Azure-LI-BYOS Image SLES15-SP6-SAP-Azure-LI-BYOS-Production Image SLES15-SP6-SAP-Azure-VLI-BYOS Image SLES15-SP6-SAP-Azure-VLI-BYOS-Production Image SLES15-SP7-SAP-Azure-LI-BYOS-Production Image SLES15-SP7-SAP-Azure-VLI-BYOS-Production Affected
SUSE Liberty Linux 10 Fixed
SUSE Liberty Linux 8 Fixed
SUSE Liberty Linux 9 Fixed
SUSE Linux Enterprise Desktop 15 SP7 SUSE Linux Enterprise Server 15 SP7 SUSE Linux Enterprise Server for SAP Applications 15 SP7 Fixed

References

Advisories & patches
ADVISORY https://access.redhat.com/errata/RHSA-2026:5930 ADVISORY https://access.redhat.com/errata/RHSA-2026:5931 ADVISORY https://access.redhat.com/errata/RHSA-2026:5932 ADVISORY https://access.redhat.com/errata/RHSA-2026:6188 ADVISORY https://access.redhat.com/errata/RHSA-2026:6342 ADVISORY https://access.redhat.com/errata/RHSA-2026:6917 ADVISORY https://access.redhat.com/errata/RHSA-2026:7837 ADVISORY https://access.redhat.com/errata/RHSA-2026:7838 ADVISORY https://access.redhat.com/errata/RHSA-2026:7839 ADVISORY https://access.redhat.com/errata/RHSA-2026:7840 ADVISORY https://access.redhat.com/errata/RHSA-2026:7841 ADVISORY https://access.redhat.com/errata/RHSA-2026:7842 ADVISORY https://access.redhat.com/errata/RHSA-2026:7843 ADVISORY https://access.redhat.com/errata/RHSA-2026:7845 ADVISORY https://access.redhat.com/errata/RHSA-2026:7858 ADVISORY https://access.redhat.com/errata/RHSA-2026:8284 ADVISORY https://access.redhat.com/errata/RHSA-2026:8285 ADVISORY https://access.redhat.com/errata/RHSA-2026:8286 ADVISORY https://access.redhat.com/errata/RHSA-2026:8287 ADVISORY https://access.redhat.com/errata/RHSA-2026:8288 ADVISORY https://access.redhat.com/errata/RHSA-2026:8289 ADVISORY https://access.redhat.com/errata/RHSA-2026:8290 ADVISORY https://access.redhat.com/errata/RHSA-2026:8315 ADVISORY https://access.redhat.com/errata/RHSA-2026:8427 ADVISORY https://nvd.nist.gov/vuln/detail/CVE-2026-4712 ADVISORY https://vuldb.com/?id.352749 ADVISORY https://www.suse.com/support/update/SUSE-SU-2026:1126/ ADVISORY https://www.suse.com/support/update/SUSE-SU-2026:1127/ ADVISORY https://www.suse.com/support/update/SUSE-SU-2026:1163/ ADVISORY https://www.suse.com/support/update/SUSE-SU-2026:20978/ REF https://bugzilla.mozilla.org/show_bug.cgi?id=2017666 REF https://www.mozilla.org/security/advisories/mfsa2026-20/ REF https://www.mozilla.org/security/advisories/mfsa2026-22/ REF https://www.mozilla.org/security/advisories/mfsa2026-23/ REF https://www.mozilla.org/security/advisories/mfsa2026-24/

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