Inefficient Regular Expression Complexity Vulnerability in CodeMirror Markdown Mode
CVE-2025-6493

6.9MEDIUM

Key Information:

Vendor

CodeMirror

Status
Codemirror
Vendor
CVE Published:
22 June 2025

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2025-6493?

A known vulnerability exists in the Markdown Mode of CodeMirror versions up to 5.17.0, characterized by inefficient regular expression complexity. This issue could result in performance degradation and allows for potential remote exploitation. Although specific code samples and exploits have been disclosed publicly, it's essential for users to be aware that CodeMirror 6 offers an enhanced and actively maintained alternative for mitigating this vulnerability.

Affected Version(s)

CodeMirror 5.0

CodeMirror 5.1

CodeMirror 5.2

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2025-6493 - Proof of Concept

References

https://vuldb.com/?id.313610
vdb-entry
https://vuldb.com/?ctiid.313610
signaturepermissions-required
https://vuldb.com/?submit.598875
third-party-advisory

CVSS V4

Score:
6.9
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

DayShift (VulDB User)
.
CVE-2025-6493 : Inefficient Regular Expression Complexity Vulnerability in CodeMirror Markdown Mode