Description
Privilege escalation in the DOM: Navigation component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.
Published: 2026-07-21
Score: 8.8 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Impact

This vulnerability allows an attacker to ascend privileges within Mozilla Firefox and Thunderbird by exploiting a flaw in the DOM navigation component. The issue involves CWE-269 and CWE-270, enabling an attacker to execute code with higher privileges than intended. The impact extends to any user interacting with affected web content or local files that trigger the buggy navigation logic.

Affected Systems

Mozilla Firefox versions before 153 and Mozilla Thunderbird before 153 are affected. Updating to Firefox 153 or newer, or Thunderbird 153 or newer, removes the vulnerability.

Risk and Exploitability

The CVSS score of 8.8 marks the issue as high severity, yet the EPSS score is below 1%, indicating a low likelihood of exploitation in the wild. The vulnerability is not listed in the CISA KEV catalog. While the exact attack vector is not provided, the issue resides in a browser’s DOM navigation component, so the most probable vectors involve malicious web content or a local attack that triggers the privilege escalation.

Generated by OpenCVE AI on August 5, 2026 at 02:09 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Upgrade Firefox 153 or newer.
  • Upgrade Thunderbird 153 or newer.
  • If patching cannot be done immediately, consider disabling the vulnerable DOM navigation feature via the browser’s configuration or using a sandboxed browsing environment to limit exposure.

Generated by OpenCVE AI on August 5, 2026 at 02:09 UTC.

Tracking

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Advisories

No advisories yet.

History

Tue, 28 Jul 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-270
References
Metrics threat_severity

None

 threat_severity

Important

Fri, 24 Jul 2026 21:30:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

 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'}

Wed, 22 Jul 2026 20:00:00 +0000

Type Values Removed Values Added
Description Privilege escalation in the DOM: Navigation component. This vulnerability was fixed in Firefox 153. Privilege escalation in the DOM: Navigation component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.
References

Wed, 22 Jul 2026 17:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-269
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Wed, 22 Jul 2026 01:45:00 +0000

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

Tue, 21 Jul 2026 12:45:00 +0000

Type Values Removed Values Added
Description Privilege escalation in the DOM: Navigation component. This vulnerability was fixed in Firefox 153.
Title Privilege escalation in the DOM: Navigation component
References

Subscriptions

Mozilla Firefox Thunderbird
cve-icon MITRE

Status: PUBLISHED

Assigner: mozilla

Published:

Updated: 2026-07-24T20:16:38.167Z

Reserved: 2026-07-20T21:56:19.542Z

Link: CVE-2026-16366

cve-icon Vulnrichment

Updated: 2026-07-22T15:30:35.335Z

cve-icon NVD

Status : Modified

Published: 2026-07-21T13:17:05.140

Modified: 2026-07-24T21:16:43.670

Link: CVE-2026-16366

cve-icon Redhat

Severity : Important

Publid Date: 2026-07-21T12:37:38Z

Links: CVE-2026-16366 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-08-05T02:15:03Z

Weaknesses
  • CWE-269

    Improper Privilege Management

  • CWE-270

    Privilege Context Switching Error