CVE-2026-8954: Incorrect boundary conditions, integer overflow in the Audio/Video component

Published May 19, 2026
·
Updated

Incorrect boundary conditions, integer overflow in the Audio/Video component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.

Affected Software

7 affected componentsFixes available
Mozilla Firefox<151
151
Mozilla Firefox ESR<140.11
140.11
Mozilla Thunderbird<151
151
Mozilla Thunderbird<140.11
140.11
Mozilla Firefox<140.11.0
Mozilla Firefox<151.0.0
Mozilla Thunderbird<140.11

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 151
  2. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 140.11
  3. Upgrade

    Upgrade Mozilla Firefox (Audio/Video component) to a version that resolves this vulnerability.

    Fixed in 151
  4. Upgrade

    Upgrade Mozilla Firefox ESR (Audio/Video component) to a version that resolves this vulnerability.

    Fixed in 140.11
  5. Upgrade

    Upgrade Mozilla Thunderbird (Audio/Video component) to a version that resolves this vulnerability.

    Fixed in 151
  6. Upgrade

    Upgrade Mozilla Thunderbird ESR (Audio/Video component) to a version that resolves this vulnerability.

    Fixed in 140.11

Event History

May 19, 2026
CVE Published
via Mozilla·12:00 AM
Data Sourced
via Mozilla·12:00 AM
DescriptionSeverityAffected Software
Updated
via Mozilla·12:00 AM
Affected Software
CVE Published
via MITRE·12:29 PM
Data Sourced
via MITRE·12:29 PM
Description
Data Sourced
via Red Hat·02:02 PM
DescriptionSeverityAffected Software
Data Sourced
via NVD·02:16 PM
DescriptionSeverityWeaknessAffected Software
Jun 29, 58424
Event
via FIRST·10:21 AM

Parent advisories

This vulnerability appears in the following advisories.

Peer vulnerabilities

Found alongside the following vulnerabilities.

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Frequently Asked Questions

1

What is the severity of CVE-2026-8954?

CVE-2026-8954 is classified as a critical vulnerability due to its potential for causing integer overflow and incorrect boundary conditions.

2

How do I fix CVE-2026-8954?

To fix CVE-2026-8954, update your Firefox to version 151, Firefox ESR to 140.11, Thunderbird to version 151, or Thunderbird ESR to 140.11.

3

Which software is affected by CVE-2026-8954?

CVE-2026-8954 affects Mozilla Firefox up to version 151, Firefox ESR up to version 140.11, and Thunderbird up to version 151.

4

What type of vulnerability is CVE-2026-8954?

CVE-2026-8954 is an integer overflow vulnerability resulting from incorrect boundary conditions in the Audio/Video component.

5

What versions of Firefox and Thunderbird should I avoid due to CVE-2026-8954?

Avoid using versions of Firefox below 151 and Thunderbird below 151, as these are vulnerable to CVE-2026-8954.

Company

Resources

Contact

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