CVE-2026-8949: Vulnerability in Mozilla Firefox
Integer overflow in the Widget: Win32 component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
AI Analysis
Technical Summary
An integer overflow vulnerability exists in the Widget: Win32 component of Mozilla Firefox, identified as CVE-2026-8949. This flaw could potentially lead to security issues, but the Mozilla security advisories rate its impact as moderate. The vulnerability was resolved in Firefox 151 and Firefox ESR 140.11. No active exploitation has been reported. The vendor advisories provide official patches and remediation guidance.
Potential Impact
The vulnerability could allow an attacker to cause unintended behavior due to integer overflow in the Widget: Win32 component. The impact is assessed as moderate by Mozilla, indicating a potential but limited security risk. There are no reports of exploitation in the wild, reducing immediate threat urgency.
Mitigation Recommendations
Mozilla has released official fixes for this vulnerability in Firefox 151 and Firefox ESR 140.11. Users and administrators should update to these versions or later to remediate the issue. Since the vulnerability is fixed, no additional mitigation actions are required beyond applying the official patches.
CVE-2026-8949: Vulnerability in Mozilla Firefox
Description
Integer overflow in the Widget: Win32 component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
An integer overflow vulnerability exists in the Widget: Win32 component of Mozilla Firefox, identified as CVE-2026-8949. This flaw could potentially lead to security issues, but the Mozilla security advisories rate its impact as moderate. The vulnerability was resolved in Firefox 151 and Firefox ESR 140.11. No active exploitation has been reported. The vendor advisories provide official patches and remediation guidance.
Potential Impact
The vulnerability could allow an attacker to cause unintended behavior due to integer overflow in the Widget: Win32 component. The impact is assessed as moderate by Mozilla, indicating a potential but limited security risk. There are no reports of exploitation in the wild, reducing immediate threat urgency.
Mitigation Recommendations
Mozilla has released official fixes for this vulnerability in Firefox 151 and Firefox ESR 140.11. Users and administrators should update to these versions or later to remediate the issue. Since the vulnerability is fixed, no additional mitigation actions are required beyond applying the official patches.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-05-19T12:29:40.080Z
- Cvss Version
- null
- State
- PUBLISHED
- Remediation Level
- null
- Vendor Advisory Urls
- [{"url":"https://www.mozilla.org/security/advisories/mfsa2026-46/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-48/","vendor":"Mozilla"}]
Threat ID: 6a0c6779ec166c07b0a99389
Added to database: 5/19/2026, 1:36:57 PM
Last enriched: 5/19/2026, 2:07:14 PM
Last updated: 5/20/2026, 6:42:51 PM
Views: 9
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