CVE-2025-8037
Nameless cookies shadow secure cookies
CVSS Score
9.1
EPSS Score
0.0%
EPSS Percentile
0th
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.
| Vendor | mozilla |
| Product | firefox |
| Ecosystems | |
| Industries | Technology |
| Published | Jul 22, 2025 |
| Last Updated | Apr 13, 2026 |
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Affected Versions
Mozilla / Firefox
All versions affected Mozilla / Thunderbird
All versions affected References
bugzilla.mozilla.org: https://bugzilla.mozilla.org/show_bug.cgi?id=1964767 mozilla.org: https://www.mozilla.org/security/advisories/mfsa2025-56/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2025-59/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2025-61/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2025-63/
Credits
Uku Sõrmus