CVE-2025-6493

CodeMirror Markdown Mode markdown.js redos

MEDIUM
5.3
CVSS Score
Published: June 22, 2025 at 10:00 PM UTC
Updated: June 17, 2026 at 10:02 AM UTC
1 product affected across 1 vendorCodemirror

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Severity
MEDIUM5.3
Exploit prediction
EPSS 0.5%
SSVC
PoC

Description

A vulnerability was found in CodeMirror up to 5.17.0 and classified as problematic. Affected by this issue is some unknown functionality of the file mode/markdown/markdown.js of the component Markdown Mode. The manipulation leads to inefficient regular expression complexity. The attack may be launched remotely. The exploit has been disclosed to the public and may be used. 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."

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (4)

SSVC — Action Prioritization

SSVCPoCAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.3MEDIUMVulDB
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-400CWE-1333

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