CVE-2025-6429

Description

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.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
mozjs52	25.10 questing	Not in release
	25.04 plucky	Not in release
	24.10 oracular	Not in release
	24.04 LTS noble	Not in release
	22.04 LTS jammy	Not in release
	20.04 LTS focal	Ignored
	18.04 LTS bionic	Ignored
firefox	25.10 questing	Not affected
	25.04 plucky	Not affected
	24.10 oracular	Not affected
	24.04 LTS noble	Not affected
	22.04 LTS jammy	Not affected
thunderbird	25.10 questing	Not affected
	25.04 plucky	Not affected
	24.10 oracular	Not affected
	24.04 LTS noble	Not affected
	22.04 LTS jammy	Fixed 1:128.12.0+build1-0ubuntu0.22.04.1
mozjs38	25.10 questing	Not in release
	25.04 plucky	Not in release
	24.10 oracular	Not in release
	24.04 LTS noble	Not in release
	22.04 LTS jammy	Not in release
	18.04 LTS bionic	Needs evaluation
mozjs68	25.10 questing	Not in release
	25.04 plucky	Not in release
	24.10 oracular	Not in release
	24.04 LTS noble	Not in release
	22.04 LTS jammy	Not in release
	20.04 LTS focal	Ignored
mozjs78	25.10 questing	Not in release
	25.04 plucky	Not in release
	24.10 oracular	Not in release
	24.04 LTS noble	Not in release
	22.04 LTS jammy	Ignored
mozjs91	25.10 questing	Not in release
	25.04 plucky	Not in release
	24.10 oracular	Not in release
	24.04 LTS noble	Not in release
	22.04 LTS jammy	Ignored
mozjs102	25.10 questing	Not in release
	25.04 plucky	Not in release
	24.10 oracular	Not in release
	24.04 LTS noble	Ignored
	22.04 LTS jammy	Ignored
mozjs115	25.10 questing	Not in release
	25.04 plucky	Ignored
	24.10 oracular	Ignored
	24.04 LTS noble	Ignored
	22.04 LTS jammy	Not in release

Notes

mdeslaur

mozjs* contain a copy of the SpiderMonkey JavaScript engine. It is not feasible to backport security fixes to the mozjs* packages, as such, marking them as ignored. starting with Ubuntu 22.04, the firefox package is just a script that installs the Firefox snap starting with Ubuntu 24.04, the thunderbird package is just a script that installs the Thunderbird snap

Severity score breakdown

Parameter	Value
Base score	6.5 · Medium
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	Required
Scope	Unchanged
Confidentiality	None
Integrity impact	High
Availability impact	None
Vector	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

References

Related Ubuntu Security Notices (USN)

USN-7663-1
Thunderbird vulnerabilities
22 July 2025

Cvss 3 Severity Score