SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2025-6493

A weakness has been identified in CodeMirror up to 5.65.20.

MEDIUM 5.5EPSS 0.53%

Does this matter?

Lower severity and a low EPSS score (0.53%). Track it; it rarely justifies an emergency change on its own.

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."

CVSS 4.0
5.5 MEDIUMCVSS: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/M
EPSS
0.53% probability · 45th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-400, CWE-1333
Source
cna@vuldb.com
EPSS trend
0%3%5%26 October 2026: 0.53%26 October 202626 October 2026

EPSS 0.5% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.