CVE-2021-23639: The package md-to-pdf before 5.0.0 are vulnerable to Remote Code Execution (RCE) due to utilizing the library

This week

CRITICAL 9.8REMOTEUPGRADE

CVE-2021-23639 is a critical-severity flaw (CVSS 9.8) affecting markdown to pdf. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The package md-to-pdf before 5.0.0 are vulnerable to Remote Code Execution (RCE) due to utilizing the library gray-matter to parse front matter content, without disabling the JS engine.

Why this priority

Critical severity
EPSS top 7%: very likely to be exploited
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	5.4% (top 7%)
CISA exploited list	No
Published	2021-12-10
Last modified	2026-06-17

Publisher (CNA): Snyk · Vendor: markdown to pdf project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-12-10 20:15 UTCPublished CVE record published
2026-06-17 03:38 UTCUpdated Record last modified

markdown to pdf project markdown to pdf UPGRADE

Affected: < 5.0.0

Fixed in: 5.0.0

Safe to downgrade to: no unaffected older release

1. Check installed version

npm ls markdown-to-pdf

2. UPGRADE to 5.0.0

npm install markdown-to-pdf@">=5.0.0"

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-23639?

markdown to pdf: upgrade to 5.0.0. Exact commands for each OS are on this page.

Is CVE-2021-23639 being exploited?

CVE-2021-23639 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-23639 affect?

CVE-2021-23639 affects markdown to pdf. Severity is critical (CVSS 9.8). The package md-to-pdf before 5.0.0 are vulnerable to Remote Code Execution (RCE) due to utilizing the library gray-matter to parse front matter content, without disabling the JS engine.

How urgent is CVE-2021-23639?

Priority 67/100. Critical severity; EPSS top 7%: very likely to be exploited; Public exploit reference; Remotely exploitable, no login, no user action

References

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