CVE-2021-47837 Markdownify 1.2.0 - Persistent Cross-Site Scripting
Attackers can inject malicious scripts into markdown files that execute when rendered, potentially leading to remote code execution.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2021-47837?
CVE-2021-47837 is a medium-severity cross-site scripting vulnerability in amitmerchant1990 Markdownify, published on 16 Jan 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
Markdownify 1.2.0 contains a persistent cross-site scripting vulnerability that allows attackers to store malicious payloads within markdown files. Attackers can upload crafted markdown files with embedded scripts that execute when the file is opened, potentially enabling remote code execution.
Weakness: CWE-79
Which versions are affected by CVE-2021-47837?
How do I fix CVE-2021-47837?
No fix has been published for CVE-2021-47837 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2021-47837 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-47837 exists.
Sources
Also known as GHSA-rfvr-hv7q-m46g.