CVE-2026-49493CWE-94

Markdown Preview Enhanced Arbitrary Code Execution via Bitfield interpretJS()

High · published June 5, 2026

CVSS v4.0
8.6
EPSS
1%
Percentile
46.2
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
8.6 · HIGH
Vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
EPSS
0.00565 · 46.2th percentile
Weakness
CWE-94 · Improper Control of Generation of Code ('Code Injection')
Published
2026-06-05T17:49Z
EPSS history
Timeline
  • 05 JUN 17:49Z
    Markdown Preview Enhanced Arbitrary Code Execution via Bitfield interpretJS()
    cvelistv5