CVE-2026-8950: Vulnerability in Mozilla Firefox
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.
AI Analysis
Technical Summary
CVE-2026-8950 describes a same-origin policy bypass vulnerability affecting the Networking: HTTP component in Mozilla Firefox. The same-origin policy is a critical security mechanism that restricts how documents or scripts loaded from one origin can interact with resources from another origin. Bypassing this policy can potentially allow unauthorized cross-origin interactions. Mozilla fixed this vulnerability in Firefox 151 and Firefox ESR 140.11. The vendor advisories (MFSA 2026-46 and MFSA 2026-48) list this vulnerability among others fixed in these releases, assigning it a moderate impact rating.
Potential Impact
The vulnerability allows bypassing the same-origin policy in the Networking: HTTP component, which could enable unauthorized cross-origin resource access. The impact is rated moderate by Mozilla. There are no reports of exploitation in the wild. The fix is included in Firefox 151 and Firefox ESR 140.11, mitigating the risk for users who have updated to these versions.
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 vulnerability. No additional mitigation steps are indicated by the vendor advisory.
CVE-2026-8950: Vulnerability in Mozilla Firefox
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.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-8950 describes a same-origin policy bypass vulnerability affecting the Networking: HTTP component in Mozilla Firefox. The same-origin policy is a critical security mechanism that restricts how documents or scripts loaded from one origin can interact with resources from another origin. Bypassing this policy can potentially allow unauthorized cross-origin interactions. Mozilla fixed this vulnerability in Firefox 151 and Firefox ESR 140.11. The vendor advisories (MFSA 2026-46 and MFSA 2026-48) list this vulnerability among others fixed in these releases, assigning it a moderate impact rating.
Potential Impact
The vulnerability allows bypassing the same-origin policy in the Networking: HTTP component, which could enable unauthorized cross-origin resource access. The impact is rated moderate by Mozilla. There are no reports of exploitation in the wild. The fix is included in Firefox 151 and Firefox ESR 140.11, mitigating the risk for users who have updated to these versions.
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 vulnerability. No additional mitigation steps are indicated by the vendor advisory.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-05-19T12:29:41.562Z
- 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: 6a0c6779ec166c07b0a9938e
Added to database: 5/19/2026, 1:36:57 PM
Last enriched: 5/19/2026, 2:07:07 PM
Last updated: 5/20/2026, 1:33:50 PM
Views: 5
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