CVE-2025-6493

Name	CVE-2025-6493
Description	A weakness has been identified in CodeMirror up to 5.65.20. Affected is an unknown function of the file mode/markdown/markdown.js of the component Markdown Mode. This manipulation causes inefficient regular expression complexity. It is possible to initiate the attack remotely. The exploit has been made available to the public and could be exploited. Upgrading to version 6.0 is able to address this issue. You should upgrade the affected component. Not all code samples mentioned in the GitHub issue can be found. The repository mentions, that "CodeMirror 6 exists, and is [...] much more actively maintained."
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs	1108477

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
codemirror-js (PTS)	bullseye	5.59.2+~cs0.23.109-1	vulnerable
	bookworm	5.65.0+~cs5.83.9-2	vulnerable
	trixie	5.65.0+~cs5.83.9-3	vulnerable
	forky, sid	5.65.20+~cs5.83.25-1	vulnerable

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
codemirror-js	source	(unstable)	(unfixed)			1108477

Notes

[trixie] - codemirror-js <no-dsa> (Minor issue)
[bookworm] - codemirror-js <no-dsa> (Minor issue)
[bullseye] - codemirror-js <postponed> (Minor issue)
https://github.com/codemirror/codemirror5/issues/7128