Cyber Posture

CVE-2026-4709

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 0.0003 7.3th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Description

Incorrect boundary conditions in the Audio/Video: GMP component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

Mitigating Controls (NIST 800-53 r5)AI

prevent

Directly mandates timely remediation of known software flaws like this boundary condition vulnerability in the GMP component via vendor patches such as those in Firefox 149 and Thunderbird 149.

detect

Requires vulnerability scanning to identify deployments of vulnerable Firefox and Thunderbird versions affected by this GMP boundary condition issue.

prevent

Ensures monitoring of security advisories like MFSA 2026-20, 2026-21, and 2026-22 to facilitate prompt patching of this CVE.

Security SummaryAI

CVE-2026-4709 is a vulnerability stemming from incorrect boundary conditions in the Audio/Video: GMP component of Mozilla products. It affects Firefox versions prior to 149, Firefox ESR versions prior to 115.34 and 140.9, Thunderbird versions prior to 149 and 140.9. The issue is classified under CWE-754 (Improper Check for Unusual or Exceptional Conditions) and carries a CVSS v3.1 base score of 7.5.

Remote attackers require no privileges or user interaction to exploit this vulnerability over the network with low complexity. Successful exploitation results in high-impact denial of service, such as application crashes, with no impact on confidentiality or integrity and unchanged scope.

Mozilla security advisories (MFSA 2026-20, 2026-21, and 2026-22) and related Bugzilla entries detail the patch status, confirming fixes in the specified Firefox and Thunderbird versions. Security practitioners should prioritize updating affected installations to mitigate exposure.

Details

CWE(s)

Affected Products

mozilla
firefox
≤ 115.34.0 · ≤ 149.0 · 128.0 — 140.9.0

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 boundary condition flaw in the GMP media component directly results in application crashes, mapping to Endpoint DoS via application/system exploitation.

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

References