How severe is GHSA-2h8j-8r9p-849f?

GHSA-2h8j-8r9p-849f has a CVSS score of 5.4/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by GHSA-2h8j-8r9p-849f?

GHSA-2h8j-8r9p-849f affects the following packages: @digitalocean/do-markdownit (npm). Ecosystems affected: npm.

How do I fix GHSA-2h8j-8r9p-849f?

No patched version of @digitalocean/do-markdownit has shipped for GHSA-2h8j-8r9p-849f yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.

How do I detect GHSA-2h8j-8r9p-849f in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @digitalocean/do-markdownit. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-2h8j-8r9p-849f if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-2h8j-8r9p-849f?

O3 pinpoints whether GHSA-2h8j-8r9p-849f is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-2h8j-8r9p-849f actively exploited in the wild?

No public exploit code has been indexed for GHSA-2h8j-8r9p-849f yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-2h8j-8r9p-849f?

GHSA-2h8j-8r9p-849f has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 28th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-2h8j-8r9p-849f?

GHSA-2h8j-8r9p-849f is classified as CWE-843 (CWE-843). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-2h8j-8r9p-849f published, and has it been updated?

GHSA-2h8j-8r9p-849f was published on September 19, 2025 and was last updated on September 22, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

GHSA-2h8j-8r9p-849f

MEDIUM

@digitalocean/do-markdownit has Type Confusion vulnerability

Also known asCVE-2025-59717

Published

Sep 19, 2025

Updated

Sep 22, 2025

Affected

1 pkg

Patched

None yet

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk28th percentile+0.30%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected

📦@digitalocean/do-markdownit

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.

Description

Overview

A type confusion issue exists in the @digitalocean/do-markdownit package. In the callout and fence_environment plugins, the allowedClasses and allowedEnvironments options are expected to be arrays of strings. If these options are provided as a single string, the code applies .includes directly on the string, resulting in substring matching instead of membership checks against an array.

Affected Versions

All versions up to and including 1.16.1 (npm).

Impact

Supplying crafted input can bypass intended allow-lists (e.g., class/environment constraints) due to substring checks, which may enable rendering of unintended classes or environments and lead to policy bypass in downstream consumers.

Mitigation

Until an upstream fix is released, ensure configuration normalization before invoking the plugins:

Validate that allowedClasses and allowedEnvironments are arrays (Array.isArray(...)), converting single strings into one-element arrays when necessary.
Consider sanitizing or strictly validating user-controlled values that influence Markdown rendering.

Affected Packages

1 total

Ecosystem	Package	Vulnerable range	Fix
📦npm	`@digitalocean/do-markdownit`	all versions	No fix

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @digitalocean/do-markdownit. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of @digitalocean/do-markdownit has shipped for GHSA-2h8j-8r9p-849f yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-2h8j-8r9p-849f is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-2h8j-8r9p-849f. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Overview A type confusion issue exists in the `@digitalocean/do-markdownit` package. In the `callout` and `fence_environment` plugins, the `allowedClasses` and `allowedEnvironments` options are expected to be arrays of strings. If these options are provided as a single string, the code applies `.includes` directly on the string, resulting in substring matching instead of membership checks against an array. ### Affected Versions All versions up to and including 1.16.1 (npm). ### Impact Supplying crafted input can bypass intended allow-lists (e.g., class/environment constraints) due to sub

O3 Security · Impact-Aware SCA

Is GHSA-2h8j-8r9p-849f in your dependencies?

O3 detects GHSA-2h8j-8r9p-849f across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works