Vulnerability · Published Jun 5, 2026 · Assigned by VulnCheck

CVE-2026-49493Markdown Preview Enhanced Arbitrary Code Execution via Bitfield interpretJS()

High 8.8

In plain English

A high-severity code injection in Markdown Preview Enhanced from shd101wyy. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 26% of all known vulnerabilities).

Severity (CVSS 3.1)8.8High

Exploit odds (30 days)0.3%top 74.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Markdown Preview Enhanced before 0.8.28 parses Bitfield fenced code blocks with interpretJS(), which evaluates the block content as code via vm.runInNewContext(), allowing arbitrary code execution. A crafted markdown document containing a malicious bitfield code block executes attacker-controlled code on the server side when the document is rendered or exported. Fixed in 0.8.28 by parsing bitfield register definitions with JSON5.parse(), since they are purely data.

Affected products (as reported)

Vendor	Product	Versions
shd101wyy	Markdown Preview Enhanced	0 – before 0.8.28

Weakness: CWE-94 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

References

Release 0.8.28 release-notes
VulnCheck Advisory: Markdown Preview Enhanced Arbitrary Code Execution via Bitfield interpretJS() third-party-advisory