CVE-2025-6493: 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 Mar...

Description

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

CVSS 3.1

5.3/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CVSS 4.0

5.5/10

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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability

0.45%

35.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

References

Timeline

Published: Jun 22, 2025
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2025-6493?

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."

How severe is CVE-2025-6493?

CVE-2025-6493 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.45% probability of exploitation in the next 30 days.

How do I fix CVE-2025-6493?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.