RCE in Shd101wyy Markdown Preview Enhanced
CVE-2026-49493
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.
Vulnerability class: RCE (Remote Code Execution)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.006 (46.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 46th percentile — 46.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000
Affected products
- Shd101wyy Markdown Preview Enhanced — versions 0
Weakness classification (CWE)
References
- github.com/shd101wyy/vscode-markdown-preview-enhanced/releases/tag/0.8.28 (release-notes)
- www.vulncheck.com/advisories/markdown-preview-enhanced-arbitrary-code-execution… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-49493?
- CVE-2026-49493 is a high-severity vulnerability in Shd101wyy Markdown Preview Enhanced, classified under Code Injection. CVSS score: 8.8/10. Published 2026-06-05.
- How severe is CVE-2026-49493?
- High severity. CVSS v3 base score is 8.8 out of 10.