CVE-2026-100831: Use-after-free in the DOM: UI Events & Focus Handling component

Published Sep 29, 2026
·
Updated

Use-after-free in the DOM: UI Events & Focus Handling component. This vulnerability was fixed in Firefox ESR 153.4 and Firefox 157.

Affected Software

2 affected componentsFixes available
Mozilla Firefox<157
157
Mozilla Firefox ESR<153.4
153.4

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 157
  2. Upgrade

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

    Fixed in 153.4
  3. Upgrade

    Upgrade Firefox ESR to a version that resolves this vulnerability.

    Fixed in 153.4
  4. Upgrade

    Upgrade Firefox to a version that resolves this vulnerability.

    Fixed in 157

Event History

Sep 29, 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·12:36 PM
Data Sourced
via MITRE·12:36 PM
Description
Data Sourced
via NVD·01:17 PM
DescriptionSeverityWeakness

Parent advisories

This vulnerability appears in the following advisories.

Frequently Asked Questions

1

Which Mozilla product lines should be reviewed for this issue?

The issue is listed for Mozilla Firefox and Mozilla Firefox ESR.

2

Does the available information identify affected or fixed versions?

No affected or fixed version numbers are provided in the available information. The referenced Mozilla advisories and Bugzilla report should be consulted for version-specific guidance.

Contact

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