Site isolation issue in the Networking component. This vulnerability was fixed in Firefox 153 and Firefox ESR 140.13.

No CVSS v4.0

No CVSS v3.1

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
Mozilla Firefox affected
Version Status Constraints
140.13 unaffected ≤ 140.*
153 unaffected ≤ *

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Project Subscriptions

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Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://bugzilla.mozilla.org/show_bug.cgi?id=2043200 cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-68/ cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-70/ cve-icon
History

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

Type Values Removed Values Added
Description Site isolation issue in the Networking component. This vulnerability was fixed in Firefox 153 and Firefox ESR 140.13.
Title Site isolation issue in the Networking component
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: mozilla

Published:

Updated: 2026-07-21T12:38:01.478Z

Reserved: 2026-07-20T21:57:05.138Z

Link: CVE-2026-16387

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses

No weakness.