Vulnerability Description
Setting a nameless cookie with an equals sign in the value shadowed other cookies. Even if the nameless cookie was set over HTTP and the shadowed cookie included the `Secure` attribute. This vulnerability was fixed in Firefox 141, Firefox ESR 140.1, Thunderbird 141, and Thunderbird 140.1.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | < 140.1 |
| Mozilla | Thunderbird | < 140.1 |
Related Weaknesses (CWE)
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1964767Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2025-56/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-59/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-61/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-63/Vendor Advisory
FAQ
What is CVE-2025-8037?
CVE-2025-8037 is a vulnerability with a CVSS score of 9.1 (CRITICAL). Setting a nameless cookie with an equals sign in the value shadowed other cookies. Even if the nameless cookie was set over HTTP and the shadowed cookie included the `Secure` attribute. This vulnerabi...
How severe is CVE-2025-8037?
CVE-2025-8037 has been rated CRITICAL with a CVSS base score of 9.1/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2025-8037?
Check the references section above for vendor advisories and patch information. Affected products include: Mozilla Firefox, Mozilla Thunderbird.