Description
Site isolation issue in the Networking: Cookies 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.
Published: 2026-08-18
Score: 8.1 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-4750-1 firefox-esr security update
Debian DLA Debian DLA DLA-4754-1 thunderbird security update
Debian DSA Debian DSA DSA-6451-1 firefox-esr security update
Debian DSA Debian DSA DSA-6461-1 thunderbird security update
History

Fri, 21 Aug 2026 18:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-200

Wed, 19 Aug 2026 16:45:00 +0000

Type Values Removed Values Added
First Time appeared Mozilla thunderbird
CPEs cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
Vendors & Products Mozilla thunderbird

Wed, 19 Aug 2026 13:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-346
Metrics cvssV3_1

{'score': 6.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

cvssV3_1

{'score': 8.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N'}


Wed, 19 Aug 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-1100
References
Metrics threat_severity

None

cvssV3_1

{'score': 6.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'}

threat_severity

Moderate


Tue, 18 Aug 2026 19:00:00 +0000

Type Values Removed Values Added
Description Site isolation issue in the Networking: Cookies component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, and Firefox ESR 153.1. Site isolation issue in the Networking: Cookies 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.
References

Tue, 18 Aug 2026 15:00:00 +0000

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

Tue, 18 Aug 2026 14:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-200

Tue, 18 Aug 2026 12:45:00 +0000

Type Values Removed Values Added
Description Site isolation issue in the Networking: Cookies component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, and Firefox ESR 153.1.
Title Site isolation issue in the Networking: Cookies component
References

Subscriptions

Mozilla Firefox Thunderbird
cve-icon MITRE

Status: PUBLISHED

Assigner: mozilla

Published:

Updated: 2026-08-19T12:52:57.196Z

Reserved: 2026-08-17T11:58:26.320Z

Link: CVE-2026-74962

cve-icon Vulnrichment

Updated: 2026-08-19T12:51:49.083Z

cve-icon NVD

Status : Analyzed

Published: 2026-08-18T13:17:33.430

Modified: 2026-08-19T16:38:05.230

Link: CVE-2026-74962

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-08-18T12:23:31Z

Links: CVE-2026-74962 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-08-21T20:00:13Z

Weaknesses