CVE catalog

CVE-2025-6493

codemirror-js: CVE-2025-6493

Severity: Medium · CVSS 5.3CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Published: Jun 22, 2025, 10:00:10 PM UTC
Source: [NVD] · [CVE record]
EPSS: 0.53% · Oct 25, 2026

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."

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

Distribution	Package	Release	Version	Status
Debian	codemirror-js	sid	`5.65.20+~cs5.83.25-1`	vulnerable
Debian	codemirror-js	forky	`5.65.20+~cs5.83.25-1`	vulnerable
Debian	codemirror-js	trixie	`5.65.0+~cs5.83.9-3`	vulnerable
Debian	codemirror-js	bookworm	`5.65.0+~cs5.83.9-2`	vulnerable

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	codemirror-js	source	sid	`(unfixed)`	not yet assigned	Not reported	[1108477]
Debian	codemirror-js	source	forky	`(unfixed)`	not yet assigned	Not reported	[1108477]
Debian	codemirror-js	source	trixie	`(unfixed)`	not yet assigned	Not reported	[1108477]
Debian	codemirror-js	source	bookworm	`(unfixed)`	not yet assigned	Not reported	[1108477]

[Debian bug #1108477]

Notes

[trixie] codemirror-js: Minor issue [bookworm] codemirror-js: Minor issue

OpenFactory catalog packages

[Debian 12 (Bookworm)]

[libjs-codemirror]Affected
Source package: [codemirror-js]
Details (2)
- 5.65.0+~cs5.83.9-2 · all · bookworm
  Affected
  dsa · codemirror-js · debian · bookworm; dsa · codemirror-js · debian · 12
- 5.65.0+~cs5.83.9-2 · all · bookworm
  Affected
  dsa · codemirror-js · debian · bookworm; dsa · codemirror-js · debian · 12

[Debian 13 (Trixie)]

[libjs-codemirror]Affected
Source package: [codemirror-js]
Details (2)
- 5.65.0+~cs5.83.9-3 · all · trixie
  Affected
  dsa · codemirror-js · debian · 13
- 5.65.0+~cs5.83.9-3 · all · trixie
  Affected
  dsa · codemirror-js · debian · 13

Observed: Oct 24, 2026, 9:37:56 PM UTC

References

[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX]