Vikunja 2.6.0 Broken Access Control via Inherited Project Permissions

{
  "id": "535cc3961f7756651889971f13336bd39302196350936ee1b8afa8eafd19256b",
  "url": "https://osv.dev/vulnerability/CVE-2026-111920",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Vikunja 2.6.0 Broken Access Control via Inherited Project Permissions",
    "summary": "Vikunja 2.6.0 contains a broken access control flaw in getProjectAccessForUser (pkg/models/project_access.go), which resolves a user's effective project permission as the maximum over the project tree, silently overriding explicit lower-permission shares on sub-projects. A collaborator with write access on a parent project but read-only access to a child project can modify the child project's tasks and content.",
    "evidence": "osv:CVE-2026-111920",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-111920",
      "aliases": [
        "CVE-2026-111920",
        "GHSA-pjr3-86v4-5p7w",
        "GO-2026-6745"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/go-vikunja/vikunja",
              "type": "GIT",
              "events": [
                {
                  "introduced": "a4218eeb8fb3ada95e14a2331731524c9120d5bd"
                },
                {
                  "last_affected": "a4218eeb8fb3ada95e14a2331731524c9120d5bd"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "2.6.0"
                      },
                      {
                        "last_affected": "2.6.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandaloneSingleVersion"
                  }
                ]
              }
            }
          ],
          "versions": [
            "2.6.0",
            "v2.6.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-111920.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:36.572422013Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/111xxx/CVE-2026-111920.json",
        "https://github.com/go-vikunja/vikunja/security/advisories/GHSA-pjr3-86v4-5p7w",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-111920",
        "https://www.vulncheck.com/advisories/vikunja-2.6.0-broken-access-control-via-inherited-project-permissions"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-269"
        ],
        "cna_assigner": "VulnCheck",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/111xxx/CVE-2026-111920.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-111920",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 503929,
  "published_at": "2026-10-17T18:46:34.636+00:00"
}