Markdown Preview Enhanced: One Click RCE via Markdown Link Command Injection on Windows

published 2026-10-14 25 d ago modified 2026-10-16 24 d ago also EUVD-2026-101581

cvss: 8.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 37%
public exploits: 0; none known

Markdown Preview Enhanced is a Markdown preview extension for Visual Studio Code. Prior to 0.8.28, Markdown Preview Enhanced preview-link handling passes a decoded, Markdown-controlled link target to a Windows file-opening helper that invokes child_process.exec with the start command. When a Windows user opens an untrusted Markdown file and clicks a crafted external or unsupported-scheme link, shell metacharacters in the decoded target are interpreted by cmd.exe as command separators, allowing an attacker-selected command to run with the privileges of the current VS Code user. The attack requires one normal preview-link click but does not require malicious workspace configuration, script execution to be enabled, or additional files. This issue is fixed in version 0.8.28.

Patch / fix

fixed in 1 links 6

markdown_preview_enhanced_project markdown_preview_enhanced 0.8.28

github.com/shd101wyy/crossnote@5588ca2 commit
github.com/shd101wyy/vscode-markdown-preview-enhanced@dcd8028 commit
github.com/shd101wyy/crossnote#442 pull request
github.com/shd101wyy/vscode-markdown-preview-enhanced#2318 pull request
github.com/shd101wyy/crossnote/releases/tag/0.9.29 release
github.com/shd101wyy/vscode-markdown-preview-enhanced/releases/tag/0.… release

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 25 d ago (2026-10-15)

Exploit prediction

0.43% chance of exploitation in the next 30 days, higher than 37% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	8.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected products

shd101wyy vscode-markdown-preview-enhanced

Classification

Weakness

CWE-78 Improper Neutralization of Special Elements used in an OS Command

References

Sources

CVE List CVE-2026-54525
NVD CVE-2026-54525

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary