{"id":"CVE-2026-91985","title":"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","summary":"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-…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","cwe":["CWE-200","CWE-639","CWE-862"],"vendor":"go-vikunja","product":"vikunja","affected":["vikunja < 2.6.0"],"published":"2026-09-15","updated":"2026-09-16","sourceUpdated":"2026-09-16T19:49:18.987","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-91985","references":[{"url":"https://github.com/go-vikunja/vikunja/security/advisories/GHSA-qfwc-vx6f-3g6g","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/vikunja-before-2.6.0-privilege-escalation-via-link-share-hash","label":"disclosure@vulncheck.com"},{"url":"https://github.com/go-vikunja/vikunja/security/advisories/GHSA-qfwc-vx6f-3g6g","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-91985"},{"url":"https://github.com/go-vikunja/vikunja/pull/3688"},{"url":"https://github.com/go-vikunja/vikunja/commit/077dc4de79ce6f1ab59215a2c7bf9b30423685f2"},{"url":"https://github.com/go-vikunja/vikunja/releases/tag/v2.6.0"},{"url":"https://github.com/advisories/GHSA-qfwc-vx6f-3g6g"},{"url":"https://github.com/go-vikunja/vikunja"}],"tags":["nvd","cve.org","exploit-available","ghsa","go","osv"],"exploitAvailable":true,"ssvc":{"exploitation":"poc","automatable":"yes","technicalImpact":"partial","timestamp":"2026-09-15T16:03:46.456174Z"},"ingestedAt":"2026-09-15T15:39:12.910Z","epss":0.00432,"epssPercentile":0.37314,"aliases":["GHSA-qfwc-vx6f-3g6g","GO-2026-6747"],"ecosystem":"go","patched":["code.vikunja.io/api 2.6.0"],"slug":"CVE-2026-91985","body":"## Overview\n\nVikunja 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2026-91985)\n\nAffected packages:\n\n- `code.vikunja.io/api <= 2.5.0`\n\nPatched in:\n\n- `code.vikunja.io/api 2.6.0`\n\nSource: https://github.com/advisories/GHSA-qfwc-vx6f-3g6g","depth":"midnight","depthScore":53,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[{"seq":204289,"id":"CVE-2026-91985","ts":1789490447604,"field":"exploit_available","old":"false","new":"true"}]}