# CVE-2026-52783

## Summary

- **CVE ID:** CVE-2026-52783
- **Severity:** HIGH
- **CVSS Score:** 8.2 (CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N)
- **CWE:** CWE-313
- **Published:** Jun 26, 2026
- **Last Modified:** Jun 26, 2026

## Description

OpenProject is open-source, web-based project management software. Prior to 17.3.3 and 17.4.1, OpenProject's Storages module writes the OneDrive/SharePoint userless OAuth access_token plaintext to Rails.cache under the deterministic key storage.<id>.httpx_access_token, repopulated continuously by an hourly cron and every userless-OAuth call site (see Write cadence). None of the three allowed cache backends (file_store, memcache, redis) encrypts at rest. An attacker with read access to the cache backend recovers the Azure-AD application-tier bearer with an anonymous get over the memcached binary protocol (or the equivalent against Redis). This vulnerability is fixed in 17.3.3 and 17.4.1.

## Affected Products

- opf — openproject (< 17.3.3)
- opf — openproject (>= 17.4.0, < 17.4.1)

## References

- [CNA](https://github.com/opf/openproject/security/advisories/GHSA-h83w-5q5x-pq27)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.20%
- **EPSS Percentile:** 9.9

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._