Security Digest · Vulnerability record
CVE-2025-65108: md-to-pdf vulnerable to arbitrary JavaScript code execution when parsing front matter
md-to-pdf is a CLI tool for converting Markdown files to PDF using Node.js and headless Chrome.
CVSS 10.0 Critical EPSS 0.9% · p60
Should you act?
Critical and remotely reachable
No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.
- Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.9%, percentile 60: FIRST’s model estimates a 0.9% chance of exploitation activity in the next 30 days, higher than 60% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes
md-to-pdf(npm) < 5.2.5, fixed in 5.2.5. Check your lockfile, including transitive dependencies.
What it is
md-to-pdf is a CLI tool for converting Markdown files to PDF using Node.js and headless Chrome. Prior to version 5.2.5, a Markdown front-matter block that contains JavaScript delimiter causes the JS engine in gray-matter library to execute arbitrary code in the Markdown to PDF converter process of md-to-pdf library, resulting in remote code execution. This issue has been patched in version 5.2.5.
From the GitHub advisory
Summary A Markdown front-matter block that contains JavaScript delimiter causes the JS engine in gray-matter library to execute arbitrary code in the Markdown to PDF converter process of md-to-pdf library, resulting in remote code execution.
Details md-to-pdf uses the gray-matter library to parse front-matter. Gray-matter exposes a JavaScript engine that, when enabled or triggered by certain front-matter delimiters (e.g. ---js or ---javascript), will evaluate the front-matter contents as JavaScript. If user-supplied Markdown is fed to md-to-pdf and the front-matter contains malicious JS, the converter process will execute that code.
PoC
Running the PoC on Windows launches the calculator application, demonstrating arbitrary code execution.
Impact
Weakness type: CWE-94.
Product: md-to-pdf (npm) · Assigned by: GitHub_M · Published: 2025-11-21
Affected and fixed versions
| Ecosystem | Package | Vulnerable | First fixed |
|---|---|---|---|
| npm | md-to-pdf | < 5.2.5 | 5.2.5 |
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| simonhaenisch | md-to-pdf | < 5.2.5 |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_M | 3.1 | 10 Critical | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
| GitHub | 3.1 | 10.0 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
- Attack vector: network (remotely reachable)
- Attack complexity: low
- Privileges required: none (no login)
- User interaction: none
- Scope: changed (can affect other components)
CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.
Exploitation and urgency
- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc, automatable yes, technical impact total.
- FIRST EPSS (model of 2026-10-21): 0.93% probability of exploitation activity in the next 30 days; percentile 60.
Timeline
- — GitHub-reviewed advisory GHSA-547r-qmjm-8hvw published (critical)
- — CVE record published by GitHub_M
- — CVE record last updated
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vulnerability records
- GitHub Advisory GHSA-547r-qmjm-8hvw github.com
- CVE.org record CVE-2025-65108 cve.org
- NVD entry CVE-2025-65108 nvd.nist.gov
Other references from the CVE record and advisory
- github.com github.com
- github.com github.com