Improper input validation in Opf Openproject

CVE-2026-52780

OpenProject is open-source, web-based project management software. Prior to 17.3.3 and 17.4.1, cache store poisoning leads to Remote Code Execution (RCE). This vulnerability is fixed in 17.3.3 and 17.4.1.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.6 (Critical). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.004 (30.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 31st percentile — 30.5% 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-2026-52780: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-52780?
CVE-2026-52780 is a critical-severity vulnerability in Opf Openproject, classified under Improper Input Validation. CVSS score: 9.6/10. Published 2026-06-26.
How severe is CVE-2026-52780?
Critical severity. CVSS v3 base score is 9.6 out of 10.