CVE-2026-44696
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.
- No active-exploitation, high-EPSS, or public-exploit signals - routine patching cadence
Exploitation evidence
1 of 7 sourcesCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:NATT&CK techniques
1Techniques this CVE enables. Pills with a solid outline are high confidence - named directly in ATT&CK or Nuclei, or human-curated by CTID; the rest are inferred from the weakness type using MITRE's CVE Mapping Methodology and the CWE → CAPEC chain. Broad, generic-weakness guesses are filtered out. A small N× marks a technique that N independent sources agree on.
▤ Build a SIEM detection for these techniquesCAPEC attack patterns
6Attack patterns this CVE enables - the bridge from weakness to ATT&CK technique.