CVE-2026-16349
Received Received - Intake

Same-origin policy bypass in Firefox DOM Navigation

Publication date: 2026-07-21

Last updated on: 2026-07-21

Assigner: Mozilla Corporation

Description
Same-origin policy bypass in the DOM: Navigation component. This vulnerability was fixed in Firefox 153, Firefox ESR 115.38, and Firefox ESR 140.13.

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Meta Information

Published
2026-07-21
Last Modified
2026-07-21
Generated
2026-07-21
AI Q&A
2026-07-21
EPSS Evaluated
N/A
NVD
CVE-2026-16349
EUVD
EUVD-2026-46189

Affected Vendors & Products

Showing 7 associated CPEs
Vendor Product Version / Range
mozilla firefox From 152 (exc)
mozilla firefox_esr 115.38
mozilla firefox_esr 140.13
mozilla firefox 153
mozilla firefox 115.38
mozilla firefox 140.13
mozilla firefox From 153 (exc)

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Exploitability

CWE
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KEV
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CWE ID Description
CWE-UNKNOWN

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Executive Summary

CVE-2026-16349 is a same-origin policy bypass in Firefox's DOM Navigation component. This flaw allows malicious websites to bypass security restrictions and interact with data from other sites, potentially enabling unauthorized actions or data theft.

Detection Guidance

To detect this vulnerability, check the installed Firefox version on your system. Compare it against the fixed versions: Firefox 153, Firefox ESR 115.38, or Firefox ESR 140.13. If your version is older, the system is vulnerable.

Impact Analysis

This vulnerability could allow attackers to access sensitive data from other websites you visit, perform unauthorized actions on your behalf, or steal cookies and session tokens. It primarily affects users of vulnerable Firefox versions.

Compliance Impact

This vulnerability could lead to unauthorized access or manipulation of sensitive data across different websites, which may violate compliance requirements under GDPR (data protection) and HIPAA (health information privacy). Unauthorized data exposure or theft could result in non-compliance with these regulations.

Mitigation Strategies

Update Firefox to version 153 or later, Firefox ESR 115.38, or Firefox ESR 140.13 immediately. If updates are unavailable, consider temporarily disabling JavaScript in the browser or using alternative browsers until patched.

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