{"id":"CVE-2026-91985","summary":"Vikunja before 2.6.0 Privilege Escalation via Link Share Hash","details":"Vikunja before 2.6.0 fails to properly restrict access to the link-share hash field in single-share read endpoints, allowing read-only members to obtain the share's secret credential. Attackers can exchange the disclosed hash for a link-share JWT at the share's permission level to escalate privileges and perform unauthorized writes or administrative actions.","aliases":["GHSA-qfwc-vx6f-3g6g"],"modified":"2026-09-17T03:47:26.124045633Z","published":"2026-09-15T15:18:28.282Z","database_specific":{"cna_assigner":"VulnCheck","cwe_ids":["CWE-200"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/91xxx/CVE-2026-91985.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/91xxx/CVE-2026-91985.json"},{"type":"ADVISORY","url":"https://github.com/go-vikunja/vikunja/security/advisories/GHSA-qfwc-vx6f-3g6g"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-91985"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/vikunja-before-2.6.0-privilege-escalation-via-link-share-hash"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/go-vikunja/vikunja","events":[{"introduced":"0"},{"fixed":"a4218eeb8fb3ada95e14a2331731524c9120d5bd"}],"database_specific":{"source":["AFFECTED_FIELD","DESCRIPTION"],"extracted_events":[{"introduced":"0"},{"fixed":"2.6.0"}]}}],"versions":["v2.5.0","v2.4.0","v2.3.0","v2.2.2","v2.2.1","v2.2.0","v2.1.0","v2.0.0","v1.1.0","v1.0.0","v1.0.0-rc4","v1.0.0-rc3","v1.0.0-rc2","v1.0.0-rc1","v1.0.0-rc0","v0.24.1","v0.23.0","v0.22.1","v0.22.0","v0.21.0","v0.20.4","v0.20.3","v0.20.1","v0.20.0","v0.19.2","v0.19.1","v0.19.0","v0.18.1","v0.18.0","v0.17.0","v0.16.0","v0.15.0","v0.14.0","v0.13","v0.12","v0.11","v0.10","v0.9","v0.8","v0.7","v0.6","v0.5","v0.4","v0.3","v0.2","v0.1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-91985.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N"}]}