XSS in Openproject

CVE-2026-23625

OpenProject is an open-source, web-based project management software. Versions 16.3.0 through 16.6.4 are affected by a stored cross-site scripting vulnerability in the Roadmap view. OpenProject’s roadmap view renders the “Related work packages” list for each version. When a version contains work packages from a different project (e.g., a subproject), the helper link_to_work_package prepends package.project.to_s to the link and returns the entire string with .html_safe. Because project names are user-controlled and no escaping happens before calling html_safe, any HTML placed in a subproject name is injected verbatim into the page. The underlying issue is mitigated in versions 16.6.5 and 17.0.0 by setting a `X-Content-Type-Options: nosniff` header, which was in place until a refactoring move to Rails standard content-security policy, which did not properly apply this header in the new configuration since OpenProject 16.3.0. Those who cannot upgrade their installations should ensure that they add a X-Content-Type-Options: nosniff header in their proxying web application server.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.7 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.002 (14.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 15th percentile — 14.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-23625: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-23625?
CVE-2026-23625 is a high-severity vulnerability in Openproject, classified under Cross-site Scripting. CVSS score: 8.7/10. Published 2026-01-19.
How severe is CVE-2026-23625?
High severity. CVSS v3 base score is 8.7 out of 10.