CVE-2021-47836 Markdown Explorer 0.1.1 - Persistent Cross-Site Scripting
Attackers can execute arbitrary code on the host by uploading markdown files with JavaScript payloads in Markdown Explorer.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2021-47836?
CVE-2021-47836 is a medium-severity cross-site scripting vulnerability in jersou Markdown Explorer, published on 16 Jan 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Markdown Explorer 0.1.1 contains a cross-site scripting vulnerability that allows attackers to inject malicious code through file uploads and editor inputs. Attackers can upload markdown files with embedded JavaScript payloads that execute in the application's privileged renderer context, allowing code execution on the host.
Weakness: CWE-79
Which versions are affected by CVE-2021-47836?
How do I fix CVE-2021-47836?
No fix has been published for CVE-2021-47836 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-2021-47836 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-47836 exists.
Sources
Also known as GHSA-gj7m-5vcr-wh6x.