CVE-2026-44696 OpenProject: Stored CSS injection via Sanitize::Config::RELAXED[:css] enables phishing overlays and data exfiltration
Authenticated users can inject malicious CSS to create phishing overlays and exfiltrate data in OpenProject project management software.
- 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-2026-44696?
CVE-2026-44696 is a medium-severity cross-site scripting vulnerability in opf openproject, published on 26 Jun 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
OpenProject is open-source, web-based project management software. Prior to 17.4.0, OpenProject's rich text (markdown) rendering pipeline uses Sanitize::Config::RELAXED[:css] for inline style sanitization. This configuration permits essentially all CSS properties in style attributes on permitted HTML elements (figure, img, table, th, tr, td). This allows any authenticated user with write access to formattable text fields (work package descriptions, comments, project descriptions, news) to inject CSS This vulnerability is fixed in 17.4.0.
Weakness: CWE-79
Which versions are affected by CVE-2026-44696?
How do I fix CVE-2026-44696?
No fix has been published for CVE-2026-44696 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-2026-44696 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-44696 exists.
Sources
Also known as GHSA-j9q2-49mp-hmq5.