CVE-2025-59717 @digitalocean/do-markdownit has Type Confusion vulnerability
An attacker can bypass allowed class/environment restrictions in the markdown renderer by exploiting substring matching logic when string configurations are used.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-59717?
CVE-2025-59717 is a medium-severity vulnerability in @digitalocean/do-markdownit, published on 19 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the @digitalocean/do-markdownit package through 1.16.1 (in npm), the callout and fence_environment plugins perform .includes substring matching if allowedClasses or allowedEnvironments is a string (instead of an array).
Weakness: CWE-843
Which versions are affected by CVE-2025-59717?
2 open source packages ship an affected version, including @digitalocean/do-markdownit. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
@digitalocean/do-markdownit npm | All versions to 1.16.1 | None |
@digitalocean/do-markdownit npm | All versions to 1.16.1 | None |
Products include Digitalocean Do-Markdownit.
How do I fix CVE-2025-59717?
No fix has been published for CVE-2025-59717 yet. Limit exposure of the affected software until one is available.
Is CVE-2025-59717 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-59717 exists.
Sources
Also known as GHSA-2h8j-8r9p-849f.