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

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction Required

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploitation none

Automatable no

Technical Impact total

Affected Vendors & Products

Vendors Products
Mozilla
  • Firefox
  • Thunderbird

Configuration 1 [-]

OR cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*

No data.

References
Link Providers
https://bugzilla.mozilla.org/show_bug.cgi?id=2067172 cve-icon cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2026-100831 cve-icon
https://www.cve.org/CVERecord?id=CVE-2026-100831 cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-100/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-101/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-103/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-97/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-97/#CVE-2026-100831 cve-icon
History

Tue, 13 Oct 2026 15:45:00 +0000

Type Values Removed Values Added
First Time appeared Mozilla thunderbird
CPEs cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
Vendors & Products Mozilla thunderbird

Tue, 06 Oct 2026 12:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-825
References
Metrics threat_severity

None

 threat_severity

Low

Wed, 30 Sep 2026 17:45:00 +0000

Type Values Removed Values Added
Description Use-after-free in the DOM: UI Events & Focus Handling component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, and Firefox 157. Use-after-free in the DOM: UI Events & Focus Handling component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 153.4, and Firefox 157.
References

Wed, 30 Sep 2026 17:30:00 +0000

Type Values Removed Values Added
Description Use-after-free in the DOM: UI Events & Focus Handling component. This vulnerability was fixed in Firefox ESR 153.4 and Firefox 157. Use-after-free in the DOM: UI Events & Focus Handling component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, and Firefox 157.
References

Tue, 29 Sep 2026 15:45:00 +0000

Type Values Removed Values Added
First Time appeared Mozilla
Mozilla firefox
Vendors & Products Mozilla
Mozilla firefox

Tue, 29 Sep 2026 14:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-416
Metrics cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Tue, 29 Sep 2026 13:15:00 +0000

Type Values Removed Values Added
Description Use-after-free in the DOM: UI Events & Focus Handling component. This vulnerability was fixed in Firefox ESR 153.4 and Firefox 157.
Title Use-after-free in the DOM: UI Events & Focus Handling component
References
cve-icon MITRE

Status: PUBLISHED

Assigner: mozilla

Published: 2026-09-29T12:36:35.297Z

Updated: 2026-09-30T17:21:15.823Z

Reserved: 2026-09-26T19:19:03.382Z

Link: CVE-2026-100831

cve-icon Vulnrichment

Updated: 2026-09-29T13:11:12.089Z

cve-icon NVD

Status : Analyzed

Published: 2026-09-29T13:17:48.350

Modified: 2026-10-13T15:27:24.120

Link: CVE-2026-100831

cve-icon Redhat

Severity : Low

Publid Date: 2026-09-29T12:36:35Z

Links: CVE-2026-100831 - Bugzilla