CVE-2026-53758 Emlog: Stored XSS via Parsedown Markdown Processing - Raw HTML Not Sanitized
Attackers can inject malicious scripts via Markdown content in Emlog, leading to stored XSS affecting all site visitors.
- 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-2026-53758?
CVE-2026-53758 is a high-severity cross-site scripting vulnerability in emlog, published on 4 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Emlog is an open source website building system. In versions 2.6.29 and prior, article content is processed by Parsedown without enabling safe mode, which means raw HTML including <script> tags embedded in Markdown is passed through unescaped. The output is rendered with no additional sanitization, resulting in stored XSS visible to all site visitors. At time of publication, there are no publicly known patches.
Weakness: CWE-79
Which versions are affected by CVE-2026-53758?
How do I fix CVE-2026-53758?
No fix has been published for CVE-2026-53758 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-2026-53758 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-53758 exists.
Sources
Also known as GHSA-35vc-2gv4-mw77.