{"id":"CVE-2025-6430","title":"When a file download is specified via the `Content-Disposition` header, that directive would be ignored if the file was included via a `&lt;embed&gt;` or `&lt;object&gt;` tag, potentially making a website vulnerable to a cross-site scrip…","summary":"When a file download is specified via the `Content-Disposition` header, that directive would be ignored if the file was included via a `&lt;embed&gt;` or `&lt;object&gt;` tag, potentially making a website vulnerable to a cross-site scrip…","severity":"medium","cvss":6.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","cwe":["CWE-79"],"vendor":"mozilla","product":"firefox","affected":["firefox < 128.12.0","firefox < 140.0"],"patched":["firefox 140.0"],"published":"2025-06-24","updated":"2026-09-30","sourceUpdated":"2026-09-30T18:10:00.190","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2025-6430","references":[{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=1971140","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2025-51/","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2025-53/","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2025-54/","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2025-55/","label":"security@mozilla.org"},{"url":"https://lists.debian.org/debian-lts-announce/2025/06/msg00029.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2025/07/msg00002.html","label":"af854a3a-2127-422b-91ae-364da2661108"}],"tags":["nvd"],"epss":0.00268,"epssPercentile":0.17077,"ingestedAt":"2026-09-30T18:17:24.444Z","slug":"CVE-2025-6430","body":"## Overview\n\nWhen a file download is specified via the `Content-Disposition` header, that directive would be ignored if the file was included via a `&lt;embed&gt;` or `&lt;object&gt;` tag, potentially making a website vulnerable to a cross-site scripting attack. This vulnerability was fixed in Firefox 140, Firefox ESR 128.12, Thunderbird 140, and Thunderbird 128.12.\n\n## Affected\n\n- `firefox < 128.12.0`\n- `firefox < 140.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `firefox 140.0`","depth":"sunlit","depthScore":34,"depthScoreParts":{"impact":33.6,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}