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VULNERABILITIES

CVE-2026-84124 Details

Description

Use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 155, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.

Metrics

CVSS 3.x Severity and Vector Strings:

CNA: CISA-ADPCVSS-B:5.4 MEDIUMVector:CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

References to Advisories, Solutions, and Tools

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URLSource(s)Tag(s)
https://bugzilla.mozilla.org/show_bug.cgi?id=2061110 [email protected]Permissions Required
https://www.mozilla.org/security/advisories/mfsa2026-82/ [email protected]Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-84/ [email protected]Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-85/ [email protected]Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-86/ [email protected]Vendor Advisory

see all 7 references

Weakness Enumeration

CWE-IDCWE NameSource
CWE-416Use After FreeCISA-ADP

Affected Products

ProductVersions
mozilla firefox
< 140.15.0
>= 141.0.0, < 153.2.0
>= 154.0.0, < 155.0.0

CPE

  • cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*

Remediation

  • No remediation found in references.
mozilla thunderbird
< 140.15.0
>= 141.0, < 153.2.0
>= 154.0, < 155.0

CPE

  • cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*

Remediation

  • No remediation found in references.

Change History

4 change records found show changes

QUICK INFO

CVE Dictionary Entry:
CVE-2026-84124
NVD Published Date:
Sep 1, 2026
NVD Last Modified:
Sep 2, 2026
Source:
[email protected]