{"id":"CVE-2025-8037","title":"Setting a nameless cookie with an equals sign in the value shadowed other cookies","summary":"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, Firefo…","severity":"critical","cvss":9.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","cwe":["CWE-614"],"vendor":"mozilla","product":"firefox","affected":["firefox < 140.1","firefox < 141.0","thunderbird < 140.1","thunderbird < 141.0"],"patched":["firefox 141.0","thunderbird 141.0"],"published":"2025-07-22","updated":"2026-09-30","sourceUpdated":"2026-09-30T18:10:00.190","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2025-8037","references":[{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=1964767","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2025-56/","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2025-59/","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2025-61/","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2025-63/","label":"security@mozilla.org"}],"tags":["nvd"],"epss":0.00234,"epssPercentile":0.12904,"ingestedAt":"2026-09-30T18:17:24.450Z","slug":"CVE-2025-8037","body":"## Overview\n\nSetting 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.\n\n## Affected\n\n- `firefox < 140.1`\n- `firefox < 141.0`\n- `thunderbird < 140.1`\n- `thunderbird < 141.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `firefox 141.0`\n- `thunderbird 141.0`","depth":"midnight","depthScore":50,"depthScoreParts":{"impact":50.1,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}