Cross-Site Scripting in simple-markdown

MEDIUM 6.1CVE-2019-9844 · GHSA-qj3f-9gmq-fwv5 · Published 09/04/2019 · updated 17/06/2026

In short

CVE-2019-9844 is a MEDIUM (CVSS 6.1) vulnerability affecting simple-markdown (khanacademy), simple-markdown.
Chance of exploitation in the next 30 days (EPSS): 1.3%, higher than 70.0% of all vulnerabilities.
Fix: update to 0.4.4 or later.

Package	Affected versions	Patched versions
simple-markdown khanacademy	`< 0.4.4`	`0.4.4`
simple-markdown npm	`< 0.4.4`	`0.4.4`

Description

Versions of simple-markdown prior to 0.4.4 are vulnerable to Cross-Site Scripting. Due to insufficient input sanitization the package may render output containing malicious JavaScript. This vulnerability can be exploited through input of links containing data or VBScript URIs and a base64-encoded payload.

Recommendation

Upgrade to version 0.4.4 or later.

NVD description

simple-markdown.js in Khan Academy simple-markdown before 0.4.4 allows XSS via a data: or vbscript: URI.

References

More vulnerabilities in simple-markdown

See all →

Running one of these products? Scan your site to see whether it exposes a vulnerable version.

Scan my site free