---
id: CVE-2026-52783
title: 'OpenProject is open-source, web-based project management software'
summary: >-
  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 …
severity: high
cvss: 8.2
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N'
cwe:
  - CWE-313
published: '2026-06-26'
updated: '2026-06-29'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-52783'
references:
  - url: 'https://github.com/opf/openproject/security/advisories/GHSA-h83w-5q5x-pq27'
    label: security-advisories@github.com
tags:
  - nvd
epss: 0.00199
epssPercentile: 0.08659
ingestedAt: '2026-06-29T14:29:18.253Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.