CVE-2025-6493 MEDIUM

CVE-2025-6493: CodeMirror Markdown Mode markdown.js redos

Vendor N/A
Product CodeMirror
Weakness CWE-1333
Published June 22, 2025
Last update September 29, 2025

CVSS base score

6.9/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P

What the vulnerability does

01Description

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."

Key dates

02Disclosure timeline

June 22, 2025 CVE published
September 29, 2025 Record updated