Description
Same-origin policy bypass in the Networking: HTTP component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
Published: 2026-05-19
Score: 9.3 Critical
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-4592-1 firefox-esr security update
Debian DLA Debian DLA DLA-4594-1 thunderbird security update
Debian DSA Debian DSA DSA-6283-1 firefox-esr security update
Debian DSA Debian DSA DSA-6288-1 thunderbird security update
History

Fri, 22 May 2026 00:15:00 +0000


Wed, 20 May 2026 15:15:00 +0000

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

Tue, 19 May 2026 18:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-200
CWE-284

Tue, 19 May 2026 17:45:00 +0000

Type Values Removed Values Added
Description Same-origin policy bypass in the Networking: HTTP component. This vulnerability was fixed in Firefox 151 and Firefox ESR 140.11. Same-origin policy bypass in the Networking: HTTP component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
References

Tue, 19 May 2026 16:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-346
Metrics cvssV3_1

{'score': 9.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N'}

ssvc

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


Tue, 19 May 2026 15:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-200
CWE-284

Tue, 19 May 2026 15:00:00 +0000

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

Tue, 19 May 2026 13:45:00 +0000

Type Values Removed Values Added
Description Same-origin policy bypass in the Networking: HTTP component. This vulnerability was fixed in Firefox 151 and Firefox ESR 140.11.
Title Same-origin policy bypass in the Networking: HTTP component
References

Subscriptions

Mozilla Firefox Thunderbird
cve-icon MITRE

Status: PUBLISHED

Assigner: mozilla

Published:

Updated: 2026-05-19T17:10:48.079Z

Reserved: 2026-05-19T12:29:41.562Z

Link: CVE-2026-8950

cve-icon Vulnrichment

Updated: 2026-05-19T15:47:23.890Z

cve-icon NVD

Status : Analyzed

Published: 2026-05-19T14:16:51.257

Modified: 2026-06-17T11:04:39.363

Link: CVE-2026-8950

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-05-19T12:29:42Z

Links: CVE-2026-8950 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-05-19T19:30:12Z

Weaknesses