Information Disclosure in Firefox's Security Component
CVE-2026-16400

7.5HIGH

Key Information:

Vendor

Mozilla
Status
Firefox
Thunderbird
Vendor
CVE Published:
21 July 2026

What is CVE-2026-16400?

A security flaw was identified in the Firefox browser related to the Document Object Model (DOM), which could allow unauthorized access to sensitive information. This vulnerability was addressed in version 153 of Firefox, enhancing the overall security framework of the application. Users are encouraged to update their browsers to the latest version to mitigate potential risks associated with this vulnerability.

Affected Version(s)

Firefox 153

Thunderbird 153

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2050430
https://www.mozilla.org/security/advisories/mfsa2026-68/
https://www.mozilla.org/security/advisories/mfsa2026-71/

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
High
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Rintaro Kawasugi
.