CVE-2026-49493

HIGH
MEDIUM Priority: 0.03 BB Relevance: 67/100
Published: 2026-06-05 Modified: 2026-10-26 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Auth Conf. Impact Integ. Impact

CVSS Vector Breakdown

AV: Network
AC: Low
PR: None
UI: Active
S: X
AT: None
VC: High
VI: High
VA: High

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.

Weakness Classification (1)

Bug Bounty Relevance

67 / 100
✓ Network accessible
✓ No authentication
✓ Low complexity

CVSS Score

8.6 / 10.0 v4.0
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/E:X/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 — Exploitation Probability

0.33%
Raw Score 0.003270
Percentile 25.7%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00327
2026-10-28
0.00327

Intelligence Sources

nvd ref →