{"uuid": "b6ef8605-9eb9-4b59-b69a-d884bf0e748e", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "GHSA-3HC7-R24J-RPWC", "type": "seen", "source": "https://gist.github.com/alon710/a1728bdb091577eae8b2ca00b65d122b", "content": "# GHSA-3HC7-R24J-RPWC: GHSA-3hc7-r24j-rpwc: Cross-Project Task Disclosure via Subtask Expansion in Vikunja\n\n> **CVSS Score:** 6.8\n> **Published:** 2026-10-09\n> **Full Report:** https://cvereports.com/reports/GHSA-3HC7-R24J-RPWC\n\n## Summary\nA cross-project information disclosure vulnerability in Vikunja allows authenticated users with read access to one project to view private task details from unauthorized projects via subtask expansion parameters.\n\n## TL;DR\nVikunja API endpoints prior to version 2.6.0 fail to apply project-level authorization filters when recursively expanding subtasks, exposing private task metadata across unauthorized project boundaries.\n\n## Exploit Status: POC\n\n## Technical Details\n\n- **CWE ID**: CWE-200 / CWE-285 / CWE-862\n- **Attack Vector**: Network (Remote REST API)\n- **CVSS v4 Score**: 6.8 (Medium)\n- **Privileges Required**: Low (Authenticated user with access to at least one project)\n- **User Interaction**: None\n- **Exploit Status**: Proof of Concept Available\n- **CISA KEV Status**: Not Listed\n\n## Affected Systems\n\n- Vikunja API prior to version 2.6.0 (code.vikunja.io/api)\n- **Vikunja API**: < 2.6.0 (Fixed in: `2.6.0`)\n\n## Mitigation\n\n- Upgrade Vikunja API component to version 2.6.0 or higher.\n- Filter request parameters matching expand[]=subtasks at the reverse proxy or WAF layer if immediate patching is delayed.\n- Audit existing cross-project subtask relationships across sensitive projects.\n\n**Remediation Steps:**\n1. Identify installed Vikunja API version using GET /api/v1/info.\n2. Update deployment manifests to target tag v2.6.0 or rebuild from commit 077dc4de79ce6f1ab59215a2c7bf9b30423685f2.\n3. Restart the API service and verify subtask expansion requests against restricted projects return 403 or strip unauthorized objects.\n\n## References\n\n- [GitHub Security Advisory GHSA-3hc7-r24j-rpwc](https://github.com/go-vikunja/vikunja/security/advisories/GHSA-3hc7-r24j-rpwc)\n- [Vikunja Pull Request #3688](https://github.com/go-vikunja/vikunja/pull/3688)\n- [Vikunja Fix Commit 077dc4de79ce6f1ab59215a2c7bf9b30423685f2](https://github.com/go-vikunja/vikunja/commit/077dc4de79ce6f1ab59215a2c7bf9b30423685f2)\n- [Vikunja v2.6.0 Release Tag](https://github.com/go-vikunja/vikunja/releases/tag/v2.6.0)\n- [Vikunja Code Repository](https://github.com/go-vikunja/vikunja)\n\n\n---\n*Generated by [CVEReports](https://cvereports.com/reports/GHSA-3HC7-R24J-RPWC) - Automated Vulnerability Intelligence*", "creation_timestamp": "2026-10-10T16:30:30.000000Z"}