CVE-2025-6430
published 2025-06-24CVE-2025-6430: When a file download is specified via the `Content-Disposition` header, that directive would be ignored if the file was included via a ` ` or ` ` tag…
PriorityP425medium6.1CVSS 3.1
AVNACLPRNUIRSCCLILAN
EPSS
0.21%
11.9th percentile
When a file download is specified via the `Content-Disposition` header, that directive would be ignored if the file was included via a ` ` or ` ` 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.
Affected
10 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | firefox | < firefox 140.0-1 (sid) | firefox 140.0-1 (sid) |
| debian | firefox-esr | < firefox 140.0-1 (sid) | firefox 140.0-1 (sid) |
| debian | thunderbird | < firefox 140.0-1 (sid) | firefox 140.0-1 (sid) |
| mozilla | firefox | < 128.12.0 | 128.12.0 |
| mozilla | firefox | < 140.0 | 140.0 |
| mozilla | firefox | — | — |
| mozilla | thunderbird | >= 0 < 1:128.12.0esr-1~deb11u1 | 1:128.12.0esr-1~deb11u1 |
| mozilla | thunderbird | >= 0 < 1:128.12.0esr-1~deb12u1 | 1:128.12.0esr-1~deb12u1 |
| mozilla | thunderbird | >= 0 < 1:128.12.0esr-1 | 1:128.12.0esr-1 |
| mozilla | thunderbird | >= 0 < 1:128.12.0esr-1 | 1:128.12.0esr-1 |
CVSS provenance
nvdv3.16.1MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
osv6.1MEDIUM
vendor_debian6.1MEDIUM
vendor_redhat6.1MEDIUM
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Ubuntu
Thunderbird vulnerabilities
vendor_ubuntu·2025-07-22
CVE-2025-4083 Thunderbird vulnerabilities
Title: Thunderbird vulnerabilities
Summary: Several security issues were fixed in Thunderbird.
Multiple security issues were discovered in Thunderbird. If a user were
tricked into opening a specially crafted website in a browsing context, an
attacker could potentially exploit these to cause a denial of service,
obtain sensitive information, bypass security restrictions, cross-site
tracing, or execute arbitrary code.
Instructions: This update uses a new upstream release, which includes additional bug
fixes. After a standard system update you need to restart thunderbird to
make all the necessary changes.
Red Hat
firefox: thunderbird: Content-Disposition header ignored when a file is included in an embed or object tag
vendor_redhat·2025-06-24·CVSS 6.1
CVE-2025-6430 [MEDIUM] CWE-79 firefox: thunderbird: 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
When a file download is specified via the `Content-Disposition` header, that directive would be ignored if the file was included via a ` ` or ` ` tag, potentially making a website vulnerable to a cross-site scripting attack. This vulnerability affects Firefox or tag, potentially making a website vulnerable to a cross-site scripting attack.
Statement: Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory.
Package: rhel10/firefox-flatpak (Red Hat Enterprise Linux 10) - Affected
Package: rhel10/thunderbird-flatpak (Red Hat Enterprise Linux 10) - Affected
Package: firefox (Red Hat Enterprise Linux 6) - Out of support scope
Debian
CVE-2025-6430: firefox - When a file download is specified via the `Content-Disposition` header, that dir...
vendor_debian·2025·CVSS 6.1
CVE-2025-6430 [MEDIUM] CVE-2025-6430: firefox - When a file download is specified via the `Content-Disposition` header, that dir...
When a file download is specified via the `Content-Disposition` header, that directive would be ignored if the file was included via a ` ` or ` ` 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.
Scope: local
sid: resolved (fixed in 140.0-1)
Mozilla
Mozilla Foundation Security Advisory 2025-54: CVE-2025-6430
vendor_mozilla·CVSS 6.1
CVE-2025-6430 [MEDIUM] Mozilla Foundation Security Advisory 2025-54: CVE-2025-6430
Mozilla Foundation Security Advisory 2025-54
CVE: CVE-2025-6430
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 140
Mozilla
Mozilla Foundation Security Advisory 2025-53: CVE-2025-6430
vendor_mozilla·CVSS 6.1
CVE-2025-6430 [MEDIUM] Mozilla Foundation Security Advisory 2025-53: CVE-2025-6430
Mozilla Foundation Security Advisory 2025-53
CVE: CVE-2025-6430
Product: Firefox ESR
Impact: moderate
Fixed in: Firefox ESR 128.12
Mozilla
Mozilla Foundation Security Advisory 2025-55: CVE-2025-6430
vendor_mozilla·CVSS 6.1
CVE-2025-6430 [MEDIUM] Mozilla Foundation Security Advisory 2025-55: CVE-2025-6430
Mozilla Foundation Security Advisory 2025-55
CVE: CVE-2025-6430
Product: Thunderbird
Impact: moderate
Fixed in: Thunderbird 128.12
Mozilla
Mozilla Foundation Security Advisory 2025-51: CVE-2025-6430
vendor_mozilla·CVSS 6.1
CVE-2025-6430 [MEDIUM] Mozilla Foundation Security Advisory 2025-51: CVE-2025-6430
Mozilla Foundation Security Advisory 2025-51
CVE: CVE-2025-6430
Product: Firefox
Impact: high
Fixed in: Firefox 140
GHSA
GHSA-fvqv-c5hj-jcrp: When a file download is specified via the `Content-Disposition` header, that directive would be ignored if the file was included via a ` ` or ` ` tag,
ghsa_unreviewed·2025-06-26
CVE-2025-6430 [MEDIUM] CWE-79 GHSA-fvqv-c5hj-jcrp: When a file download is specified via the `Content-Disposition` header, that directive would be ignored if the file was included via a ` ` or ` ` tag,
When a file download is specified via the `Content-Disposition` header, that directive would be ignored if the file was included via a ` ` or ` ` tag, potentially making a website vulnerable to a cross-site scripting attack. This vulnerability affects Firefox < 140 and Firefox ESR < 128.12.
OSV
CVE-2025-6430: When a file download is specified via the `Content-Disposition` header, that directive would be ignored if the file was included via a ` ` or ` ` tag,
osv·2025-06-24·CVSS 6.1
CVE-2025-6430 [MEDIUM] CVE-2025-6430: When a file download is specified via the `Content-Disposition` header, that directive would be ignored if the file was included via a ` ` or ` ` tag,
When a file download is specified via the `Content-Disposition` header, that directive would be ignored if the file was included via a ` ` or ` ` 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.
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2025-6430 firefox: thunderbird: Content-Disposition header ignored when a file is included in an embed or object tag
bugzilla·2025-06-24·CVSS 6.1
CVE-2025-6430 [MEDIUM] CVE-2025-6430 firefox: thunderbird: Content-Disposition header ignored when a file is included in an embed or object tag
CVE-2025-6430 firefox: thunderbird: Content-Disposition header ignored when a file is included in an embed or object tag
When a file download is specified via the `Content-Disposition` header, that directive would be ignored if the file was included via a ` ` or ` ` tag, potentially making a website vulnerable to a cross-site scripting attack. This vulnerability affects Firefox < 140 and Firefox ESR < 128.12.
Discussion:
This issue has been addressed in the following products:
Red Hat Enterprise Linux 8
Via RHSA-2025:10074 https://access.redhat.com/errata/RHSA-2025:10074
---
This issue has been addressed in the following products:
Red Hat Enterprise Linux 10
Via RHSA-2025:10073 https://access.redhat.com/errata/RHSA-2025:10073
---
This issue has been addressed in the following pr
Bugzilla
Ignoring of a Content-Disposition: attachments header leads to XSS flaws
bugzilla·2025-06-09
Ignoring of a Content-Disposition: attachments header leads to XSS flaws
Ignoring of a Content-Disposition: attachments header leads to XSS flaws
Steps to reproduce:
Description:
Product: FireFox
Version: 139.0.1
Researcher: Daniil Satyaev (Positive Technologies)
Research:
1. Upload html/xml/svg file on website.
2. Return it as downloadable file
```
Content-Type: text/html
Content-Disposition: attachment; filename=test
alert(1)
```
3. Open it from another page using or HTML tags.
```
```
Actual results:
Websites often allow users to upload their own content and return it as a downloadable file using the HTTP header Content-Disposition: attachment. Its i well known feature to avoid XSS. I've found that if a page is opened using or , the Content-Disposition header is ignored, and the files are displayed instead of being downloaded.
Expected results:
B
https://bugzilla.mozilla.org/show_bug.cgi?id=1971140https://www.mozilla.org/security/advisories/mfsa2025-51/https://www.mozilla.org/security/advisories/mfsa2025-53/https://www.mozilla.org/security/advisories/mfsa2025-54/https://www.mozilla.org/security/advisories/mfsa2025-55/https://lists.debian.org/debian-lts-announce/2025/06/msg00029.htmlhttps://lists.debian.org/debian-lts-announce/2025/07/msg00002.html
2025-06-24
Published