Integer overflow in the Widget: Win32 component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00047.

Exploitation none

Automatable yes

Technical Impact partial

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
140.11 unaffected ≤ 140.*
151 unaffected ≤ *
Mozilla Thunderbird affected
Version Status Constraints
140.11 unaffected ≤ 140.*
151 unaffected ≤ *

Configuration 1 [-]

OR cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*

No data.

OpenCVE Enrichment is a feature of OpenCVE that uses AI to automatically link vendors and products to CVEs. Learn more on GitHub.

Vendors Products
Mozilla Subscribe
Firefox Subscribe

Project Subscriptions

Vendors Products
Mozilla Subscribe
Firefox Subscribe
Thunderbird Subscribe
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=1355639 cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-46/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-48/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-50/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-51/ cve-icon cve-icon
History

Wed, 20 May 2026 15:00:00 +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 17:45:00 +0000

Type Values Removed Values Added
Description Integer overflow in the Widget: Win32 component. This vulnerability was fixed in Firefox 151 and Firefox ESR 140.11. Integer overflow in the Widget: Win32 component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
References

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 14:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-190
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

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

Type Values Removed Values Added
Description Integer overflow in the Widget: Win32 component. This vulnerability was fixed in Firefox 151 and Firefox ESR 140.11.
Title Integer overflow in the Widget: Win32 component
References

Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: mozilla

Published:

Updated: 2026-05-19T17:10:47.774Z

Reserved: 2026-05-19T12:29:40.080Z

Link: CVE-2026-8949

cve-icon Vulnrichment

Updated: 2026-05-19T14:05:17.742Z

cve-icon NVD

Status : Analyzed

Published: 2026-05-19T14:16:51.140

Modified: 2026-05-20T14:49:05.930

Link: CVE-2026-8949

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-19T19:00:12Z

Weaknesses