Firefox <149: Incorrect Boundary Conditions in Audio/Video Web Codecs
CVE-2026-4695 Published on March 24, 2026

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

NVD

Vulnerability Analysis

CVE-2026-4695 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.

Attack Vector:

NETWORK

Attack Complexity:

LOW

Privileges Required:

NONE

User Interaction:

NONE

Scope:

UNCHANGED

Confidentiality Impact:

NONE

Integrity Impact:

NONE

Availability Impact:

HIGH

Weakness Types

Improper Check for Unusual or Exceptional Conditions

The software does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the software.

Incorrect Calculation of Buffer Size

The software does not correctly calculate the size to be used when allocating a buffer, which could lead to a buffer overflow.

Products Associated with CVE-2026-4695

You can be notified by email with stack.watch whenever vulnerabilities like CVE-2026-4695 are published in these products:

Mozilla Firefox

Mozilla FireFox Extended Support Release (ESR)

Mozilla Thunderbird

Red Hat Rhel Els

Red Hat Enterprise Linux Eus

Red Hat Enterprise Linux (RHEL)

Red Hat Rhel Aus

Red Hat Rhel Eus Long Life

Red Hat Rhel E4s

Red Hat Rhel Tus

Red Hat Rhel Eus

Affected Versions

Mozilla Firefox:

Version 140.9, <= 140.* is unaffected.
Version 149, <= * is unaffected.

Mozilla Thunderbird:

Version 140.9, <= 140.* is unaffected.
Version 149, <= * is unaffected.

Red Hat Enterprise Linux 10:

Version 0:140.9.0-1.el10_1 and below * is unaffected.

Red Hat Enterprise Linux 10:

Version 0:140.9.0-1.el10_1 and below * is unaffected.

Red Hat Enterprise Linux 10.0 Extended Update Support:

Version 0:140.9.0-1.el10_0 and below * is unaffected.

Red Hat Enterprise Linux 10.0 Extended Update Support:

Version 0:140.9.0-1.el10_0 and below * is unaffected.

Red Hat Enterprise Linux 7 Extended Lifecycle Support:

Version 0:140.9.0-1.el7_9 and below * is unaffected.

Red Hat Enterprise Linux 8:

Version 0:140.9.0-1.el8_10 and below * is unaffected.

Red Hat Enterprise Linux 8:

Version 0:140.9.0-1.el8_10 and below * is unaffected.

Red Hat Enterprise Linux 8.2 Advanced Update Support:

Version 0:140.9.0-1.el8_2 and below * is unaffected.

Red Hat Enterprise Linux 8.2 Advanced Update Support:

Version 0:140.9.0-1.el8_2 and below * is unaffected.

Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support:

Version 0:140.9.0-1.el8_4 and below * is unaffected.

Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support:

Version 0:140.9.0-1.el8_4 and below * is unaffected.

Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On:

Version 0:140.9.0-1.el8_4 and below * is unaffected.

Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On:

Version 0:140.9.0-1.el8_4 and below * is unaffected.

Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support:

Version 0:140.9.0-1.el8_6 and below * is unaffected.

Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support:

Version 0:140.9.0-1.el8_6 and below * is unaffected.

Red Hat Enterprise Linux 8.6 Telecommunications Update Service:

Version 0:140.9.0-1.el8_6 and below * is unaffected.

Red Hat Enterprise Linux 8.6 Telecommunications Update Service:

Version 0:140.9.0-1.el8_6 and below * is unaffected.

Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions:

Version 0:140.9.0-1.el8_6 and below * is unaffected.

Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions:

Version 0:140.9.0-1.el8_6 and below * is unaffected.

Red Hat Enterprise Linux 8.8 Telecommunications Update Service:

Version 0:140.9.0-1.el8_8 and below * is unaffected.

Red Hat Enterprise Linux 8.8 Telecommunications Update Service:

Version 0:140.9.0-1.el8_8 and below * is unaffected.

Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions:

Version 0:140.9.0-1.el8_8 and below * is unaffected.

Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions:

Version 0:140.9.0-1.el8_8 and below * is unaffected.

Red Hat Enterprise Linux 9:

Version 0:140.9.0-1.el9_7 and below * is unaffected.

Red Hat Enterprise Linux 9:

Version 0:140.9.0-1.el9_7 and below * is unaffected.

Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions:

Version 0:140.9.0-1.el9_0 and below * is unaffected.

Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions:

Version 0:140.9.0-1.el9_0 and below * is unaffected.

Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions:

Version 0:140.9.0-1.el9_2 and below * is unaffected.

Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions:

Version 0:140.9.0-1.el9_2 and below * is unaffected.

Red Hat Enterprise Linux 9.4 Extended Update Support:

Version 0:140.9.0-1.el9_4 and below * is unaffected.

Red Hat Enterprise Linux 9.4 Extended Update Support:

Version 0:140.9.0-1.el9_4 and below * is unaffected.

Red Hat Enterprise Linux 9.6 Extended Update Support:

Version 0:140.9.0-1.el9_6 and below * is unaffected.

Red Hat Enterprise Linux 9.6 Extended Update Support:

Version 0:140.9.0-1.el9_6 and below * is unaffected.

Red Hat Enterprise Linux 10: Red Hat Enterprise Linux 10: Red Hat Enterprise Linux 6: Red Hat Enterprise Linux 6: Red Hat Enterprise Linux 7:

Exploit Probability

EPSS

0.69%

Percentile

48.95%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.

Firefox <149: Incorrect Boundary Conditions in Audio/Video Web CodecsCVE-2026-4695 Published on March 24, 2026

Vulnerability Analysis

Weakness Types

Improper Check for Unusual or Exceptional Conditions

Incorrect Calculation of Buffer Size

Products Associated with CVE-2026-4695

Affected Versions

Exploit Probability

Firefox <149: Incorrect Boundary Conditions in Audio/Video Web Codecs
CVE-2026-4695 Published on March 24, 2026