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VULNERABILITIES

CVE-2026-74960 Details

Description

Site isolation issue in the WebExtensions component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.

Metrics

CVSS 3.x Severity and Vector Strings:

CNA: CISA-ADPCVSS-B:8.1 HIGHVector:CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

References to Advisories, Solutions, and Tools

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URLSource(s)Tag(s)
https://bugzilla.mozilla.org/show_bug.cgi?id=2049148 [email protected]Permissions Required
https://www.mozilla.org/security/advisories/mfsa2026-74/ [email protected]Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-76/ [email protected]Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-77/ [email protected]Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-78/ [email protected]Vendor Advisory

see all 7 references

Weakness Enumeration

CWE-IDCWE NameSource
CWE-284Improper Access ControlCISA-ADP
CWE-346Origin Validation ErrorCISA-ADP

Affected Products

ProductVersions
mozilla firefox
< 140.14.0
>= 141.0, < 153.1.0

CPE

  • cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*

Remediation

  • No remediation found in references.
mozilla thunderbird
< 140.14.0
>= 141.0, < 153.1.0

CPE

  • cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*

Remediation

  • No remediation found in references.

Change History

4 change records found show changes

QUICK INFO

CVE Dictionary Entry:
CVE-2026-74960
NVD Published Date:
Aug 18, 2026
NVD Last Modified:
Aug 24, 2026
Source:
[email protected]
CVE-2026-74960 Details - Not Deferred