CVE-2025-6430

Content-Disposition header ignored when a file is included in an embed or object tag

Published Jun 24, 2025 CVSS 3.1 · 6.1 Medium EPSS < 1% KEV · Not listed
Description
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 scripting attack. This vulnerability was fixed in Firefox 140, Firefox ESR 128.12, Thunderbird 140, and Thunderbird 128.12.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4231-1 firefox-esr security update
Debian DLA Debian DLA DLA-4239-1 thunderbird security update
Debian DSA Debian DSA DSA-5950-1 firefox-esr security update
Debian DSA Debian DSA DSA-5959-1 thunderbird security update
EUVD EUVD EUVD-2025-21377 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 scripting attack. This vulnerability affects Firefox < 140, Firefox ESR < 128.12, Thunderbird < 140, and Thunderbird < 128.12.
Ubuntu USN Ubuntu USN USN-7663-1 Thunderbird vulnerabilities
History
Type Values Removed Values Added
Description 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 scripting attack. This vulnerability affects Firefox < 140, Firefox ESR < 128.12, Thunderbird < 140, and Thunderbird < 128.12. 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 scripting attack. This vulnerability was fixed in Firefox 140, Firefox ESR 128.12, Thunderbird 140, and Thunderbird 128.12.
Type Values Removed Values Added
Title firefox: thunderbird: Content-Disposition header ignored when a file is included in an embed or object tag Content-Disposition header ignored when a file is included in an embed or object tag
Type Values Removed Values Added
Metrics epss

{'score': 0.00037}

epss

{'score': 0.00064}

Type Values Removed Values Added
Metrics epss

{'score': 0.00032}

epss

{'score': 0.00037}

Type Values Removed Values Added
Description 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 scripting attack. This vulnerability affects Firefox < 140 and Firefox ESR < 128.12. 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 scripting attack. This vulnerability affects Firefox < 140, Firefox ESR < 128.12, Thunderbird < 140, and Thunderbird < 128.12.
References
Type Values Removed Values Added
Title firefox: Content-Disposition header ignored when a file is included in an embed or object tag firefox: thunderbird: Content-Disposition header ignored when a file is included in an embed or object tag
Type Values Removed Values Added
First Time appeared Mozilla
Mozilla firefox
CPEs cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*
cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
Vendors & Products Mozilla
Mozilla firefox
Type Values Removed Values Added
First Time appeared Redhat rhel Aus
Redhat rhel E4s
Redhat rhel Els
Redhat rhel Eus
Redhat rhel Tus
CPEs cpe:/a:redhat:enterprise_linux:9
cpe:/a:redhat:rhel_aus:8.2
cpe:/a:redhat:rhel_aus:8.4
cpe:/a:redhat:rhel_aus:8.6
cpe:/a:redhat:rhel_e4s:8.6
cpe:/a:redhat:rhel_e4s:8.8
cpe:/a:redhat:rhel_e4s:9.0
cpe:/a:redhat:rhel_e4s:9.2
cpe:/a:redhat:rhel_eus:9.4
cpe:/a:redhat:rhel_tus:8.6
cpe:/a:redhat:rhel_tus:8.8
cpe:/o:redhat:enterprise_linux:10.0
cpe:/o:redhat:rhel_els:7
Vendors & Products Redhat rhel Aus
Redhat rhel E4s
Redhat rhel Els
Redhat rhel Eus
Redhat rhel Tus
Type Values Removed Values Added
First Time appeared Redhat
Redhat enterprise Linux
CPEs cpe:/a:redhat:enterprise_linux:8
Vendors & Products Redhat
Redhat enterprise Linux
Type Values Removed Values Added
Weaknesses CWE-79
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Title firefox: Content-Disposition header ignored when a file is included in an embed or object tag
References
Metrics threat_severity

None

cvssV3_1

{'score': 6.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'}

threat_severity

Moderate

Type Values Removed Values Added
Description 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 scripting attack. This vulnerability affects Firefox < 140 and Firefox ESR < 128.12.
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
mozilla
Published
Updated
Apr 13, 2026, 2:30 PM
Reserved
Jun 20, 2025, 2:51 PM
Status
Modified
Published
Jun 24, 2025, 1:15 PM
Modified
Oct 23, 2026, 10:10 PM
Severity
Moderate
Public date
Jun 24, 2025, 12:28 PM