Cyber Posture

CVE-2026-4713

High

Published: 24 March 2026

Published
24 March 2026
Modified
13 April 2026
KEV Added
Patch
CVSS Score 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0002 6.1th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Description

Incorrect boundary conditions in the Graphics component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

Mitigating Controls (NIST 800-53 r5)AI

prevent

Requires timely identification, reporting, and patching of software flaws like the incorrect boundary conditions in the Graphics component, as addressed in Firefox 149 and Thunderbird 149 updates.

prevent

Ensures receipt and implementation of security advisories such as Mozilla MFSA 2026-20 through 2026-24, prompting updates to mitigate the vulnerability.

preventdetect

Protects against denial-of-service effects like application crashes or resource exhaustion triggered by remote exploitation of the Graphics component boundary flaw.

Security SummaryAI

CVE-2026-4713 is a vulnerability involving incorrect boundary conditions in the Graphics component of Mozilla products. It affects Firefox prior to version 149, Firefox ESR prior to 140.9, Thunderbird prior to 149, and Thunderbird prior to 140.9. The issue is classified under CWE-754 (Improper Check for Unusual or Exceptional Conditions) and received a CVSS v3.1 base score of 7.5, rated High severity due to its network accessibility, low attack complexity, lack of required privileges or user interaction, and potential for high availability impact without affecting confidentiality or integrity.

An unauthenticated attacker can exploit this vulnerability remotely over the network with low complexity and no user interaction required. Successful exploitation leads to a denial-of-service condition, such as application crashes or resource exhaustion in the affected Graphics component, disrupting browser or email client functionality for the targeted user.

Mozilla's security advisories (MFSA 2026-20, 2026-22, 2026-23, and 2026-24) and the associated Bugzilla entry (bug 2018113) detail the patches that resolve the issue. Users should update to Firefox 149, Firefox ESR 140.9, Thunderbird 149, or Thunderbird 140.9 to mitigate the vulnerability.

Details

CWE(s)

Affected Products

mozilla
firefox
≤ 140.9.0 · ≤ 149.0

MITRE ATT&CK Enterprise TechniquesAI

T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
Why these techniques?

Remote unauthenticated exploitation of the graphics boundary condition flaw directly causes application crashes or resource exhaustion (high availability impact), matching T1499.004 Application or System Exploitation for client-side DoS.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

References