CVE-2025-6429
published 2025-06-24CVE-2025-6429: Firefox could have incorrectly parsed a URL and rewritten it to the youtube.com domain when parsing the URL specified in an `embed` tag. This could have…
PriorityP431medium6.5CVSS 3.1
AVNACLPRNUIRSUCNIHAN
EPSS
0.29%
20.5th percentile
Firefox could have incorrectly parsed a URL and rewritten it to the youtube.com domain when parsing the URL specified in an `embed` tag. This could have bypassed website security checks that restricted which domains users were allowed to embed. 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
nvdv3.16.5MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
osv6.5MEDIUM
vendor_debian6.5MEDIUM
vendor_redhat6.5MEDIUM
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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: Incorrect parsing of URLs could have allowed embedding of youtube.com
vendor_redhat·2025-06-24·CVSS 6.5
CVE-2025-6429 [MEDIUM] CWE-706 firefox: thunderbird: Incorrect parsing of URLs could have allowed embedding of youtube.com
firefox: thunderbird: Incorrect parsing of URLs could have allowed embedding of youtube.com
Firefox could have incorrectly parsed a URL and rewritten it to the youtube.com domain when parsing the URL specified in an `embed` tag. This could have bypassed website security checks that restricted which domains users were allowed to embed. This vulnerability affects Firefox < 140, Firefox ESR < 128.12, Thunderbird < 140, and Thunderbird < 128.12.
A flaw was found in Firefox and Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue: Firefox could have incorrectly parsed a URL and rewritten it to the youtube.com domain when parsing the URL specified in an embed tag. This could have bypassed website security checks that restricted which domains users were allowed
Debian
CVE-2025-6429: firefox - Firefox could have incorrectly parsed a URL and rewritten it to the youtube.com ...
vendor_debian·2025·CVSS 6.5
CVE-2025-6429 [MEDIUM] CVE-2025-6429: firefox - Firefox could have incorrectly parsed a URL and rewritten it to the youtube.com ...
Firefox could have incorrectly parsed a URL and rewritten it to the youtube.com domain when parsing the URL specified in an `embed` tag. This could have bypassed website security checks that restricted which domains users were allowed to embed. 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-2025-6429
vendor_mozilla·CVSS 6.5
CVE-2025-6429 [MEDIUM] Mozilla Foundation Security Advisory 2025-54: CVE-2025-6429
Mozilla Foundation Security Advisory 2025-54
CVE: CVE-2025-6429
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 140
Mozilla
Mozilla Foundation Security Advisory 2025-55: CVE-2025-6429
vendor_mozilla·CVSS 6.5
CVE-2025-6429 [MEDIUM] Mozilla Foundation Security Advisory 2025-55: CVE-2025-6429
Mozilla Foundation Security Advisory 2025-55
CVE: CVE-2025-6429
Product: Thunderbird
Impact: moderate
Fixed in: Thunderbird 128.12
Mozilla
Mozilla Foundation Security Advisory 2025-51: CVE-2025-6429
vendor_mozilla·CVSS 6.5
CVE-2025-6429 [MEDIUM] Mozilla Foundation Security Advisory 2025-51: CVE-2025-6429
Mozilla Foundation Security Advisory 2025-51
CVE: CVE-2025-6429
Product: Firefox
Impact: high
Fixed in: Firefox 140
Mozilla
Mozilla Foundation Security Advisory 2025-53: CVE-2025-6429
vendor_mozilla·CVSS 6.5
CVE-2025-6429 [MEDIUM] Mozilla Foundation Security Advisory 2025-53: CVE-2025-6429
Mozilla Foundation Security Advisory 2025-53
CVE: CVE-2025-6429
Product: Firefox ESR
Impact: moderate
Fixed in: Firefox ESR 128.12
GHSA
GHSA-8r38-4g4q-hgvw: Firefox could have incorrectly parsed a URL and rewritten it to the youtube
ghsa_unreviewed·2025-06-26
CVE-2025-6429 [MEDIUM] CWE-116 GHSA-8r38-4g4q-hgvw: Firefox could have incorrectly parsed a URL and rewritten it to the youtube
Firefox could have incorrectly parsed a URL and rewritten it to the youtube.com domain when parsing the URL specified in an `embed` tag. This could have bypassed website security checks that restricted which domains users were allowed to embed. This vulnerability affects Firefox < 140 and Firefox ESR < 128.12.
OSV
CVE-2025-6429: Firefox could have incorrectly parsed a URL and rewritten it to the youtube
osv·2025-06-24·CVSS 6.5
CVE-2025-6429 [MEDIUM] CVE-2025-6429: Firefox could have incorrectly parsed a URL and rewritten it to the youtube
Firefox could have incorrectly parsed a URL and rewritten it to the youtube.com domain when parsing the URL specified in an `embed` tag. This could have bypassed website security checks that restricted which domains users were allowed to embed. This vulnerability affects Firefox < 140, Firefox ESR < 128.12, Thunderbird < 140, and Thunderbird < 128.12.
No detection rules found.
No public exploits indexed.
https://bugzilla.mozilla.org/show_bug.cgi?id=1970658https://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