Not a U.S. government website. NDD is an independent vulnerability database by Volerion and is not affiliated with or endorsed by NIST or NVD.
VOLERION
Volerion Security Research

NOT DEFERRED DATABASE

VULNERABILITIES

CVE-2026-84119 Details

Description

Sandbox escape due to use-after-free in the DOM: Navigation component. This vulnerability was fixed in Firefox 155, Firefox ESR 115.40, 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:9.6 CRITICALVector:CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

References to Advisories, Solutions, and Tools

By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.

URLSource(s)Tag(s)
https://bugzilla.mozilla.org/show_bug.cgi?id=2057817 [email protected]Permissions Required
https://www.mozilla.org/security/advisories/mfsa2026-82/ [email protected]Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-83/ [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

see all 8 references

Weakness Enumeration

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

Affected Products

ProductVersions
mozilla firefox
< 115.40.0
>= 116.0, < 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

5 change records found show changes

QUICK INFO

CVE Dictionary Entry:
CVE-2026-84119
NVD Published Date:
Sep 1, 2026
NVD Last Modified:
Sep 2, 2026
Source:
[email protected]
CVE-2026-84119 Details - Not Deferred