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."

Metrics

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact Low

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact Low

User Interaction None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact Low

User Interaction None

Access Vector Network

Access Complexity Low

Authentication None

Confidentiality Impact None

Integrity Impact None

Availability Impact Partial

This CVE is not in the KEV list.

The EPSS score is 0.00058.

Exploitation poc

Automatable yes

Technical Impact partial

Affected Vendors & Products

Vendors Products
Codemirror
  • Codemirror

No data.

No data.

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Vendors Products
Codemirror
  • Codemirror
Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/codemirror/codemirror5/issues/7128 cve-icon cve-icon cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2025-6493 cve-icon
https://vuldb.com/?ctiid.313610 cve-icon cve-icon cve-icon
https://vuldb.com/?id.313610 cve-icon cve-icon cve-icon
https://vuldb.com/?submit.598875 cve-icon cve-icon cve-icon
https://www.cve.org/CVERecord?id=CVE-2025-6493 cve-icon
History

Mon, 29 Sep 2025 14:00:00 +0000

Type Values Removed Values Added
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." 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."
Metrics cvssV2_0

{'score': 5, 'vector': 'AV:N/AC:L/Au:N/C:N/I:N/A:P/E:POC/RL:ND/RC:UR'}

cvssV3_0

{'score': 5.3, 'vector': 'CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P/RL:X/RC:R'}

cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P/RL:X/RC:R'}

 cvssV2_0

{'score': 5, 'vector': 'AV:N/AC:L/Au:N/C:N/I:N/A:P/E:POC/RL:OF/RC:C'}

cvssV3_0

{'score': 5.3, 'vector': 'CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C'}

cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C'}

Mon, 23 Jun 2025 17:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Mon, 23 Jun 2025 12:30:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

 threat_severity

Moderate

Sun, 22 Jun 2025 22:15:00 +0000

Type Values Removed Values Added
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."
Title CodeMirror Markdown Mode markdown.js redos
Weaknesses CWE-1333
CWE-400
References
Metrics cvssV2_0

{'score': 5, 'vector': 'AV:N/AC:L/Au:N/C:N/I:N/A:P/E:POC/RL:ND/RC:UR'}

cvssV3_0

{'score': 5.3, 'vector': 'CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P/RL:X/RC:R'}

cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P/RL:X/RC:R'}

cvssV4_0

{'score': 6.9, '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'}
cve-icon MITRE

Status: PUBLISHED

Assigner: VulDB

Published:

Updated: 2025-09-29T13:48:37.784Z

Reserved: 2025-06-22T06:17:29.313Z

Link: CVE-2025-6493

cve-icon Vulnrichment

Updated: 2025-06-23T15:43:15.272Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2025-06-22T22:15:22.430

Modified: 2025-09-29T14:16:45.380

Link: CVE-2025-6493

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-06-22T22:00:10Z

Links: CVE-2025-6493 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2025-06-23T08:17:26Z