{"cve":"CVE-2026-91985","nvd":{"published":"2026-09-15T16:17:57.010","modified":"2026-09-16T19:49:18.987","status":"Deferred","description":"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.","cvss_v4":{"vector":"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","score":8.7},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","score":7.5},"cwes":["CWE-200"],"references":["https://github.com/go-vikunja/vikunja/security/advisories/GHSA-qfwc-vx6f-3g6g","https://www.vulncheck.com/advisories/vikunja-before-2.6.0-privilege-escalation-via-link-share-hash","https://github.com/go-vikunja/vikunja/security/advisories/GHSA-qfwc-vx6f-3g6g"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:53:43.293028046+00:00"},"epss":{"cve":"CVE-2026-91985","score":0.00432,"percentile":0.37515,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-qfwc-vx6f-3g6g","url":"https://osv.dev/vulnerability/GHSA-qfwc-vx6f-3g6g","summary":"Vikunja: Read-only project members can obtain any link share's access hash via the single-share read endpoint (v1 and v2) and escalate to the share's permission level","modified":"2026-10-19T21:40:54.885980828Z","packages":[{"ecosystem":"Go","name":"code.vikunja.io/api","purl":"pkg:golang/code.vikunja.io/api","ranges":["<2.6.0"],"fixed":["2.6.0"]}]},{"id":"GO-2026-6747","url":"https://osv.dev/vulnerability/GO-2026-6747","summary":"Vikunja: Read-only project members can obtain any link share's access hash via the single-share read endpoint (v1 and v2) and escalate to the share's permission level in code.vikunja.io/api","modified":"2026-10-19T21:31:50.616440179Z","packages":[{"ecosystem":"Go","name":"code.vikunja.io/api","purl":"pkg:golang/code.vikunja.io/api","ranges":["all versions"],"fixed":[]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}