{"cve":"CVE-2026-91983","nvd":{"published":"2026-09-15T16:17:55.373","modified":"2026-09-16T20:16:09.343","status":"Deferred","description":"Vikunja before 2.6.0 contains an API token scope bypass vulnerability in task read endpoints where authorization fails to inspect query string parameters. Attackers with limited token scopes can use the expand parameter to access restricted data like comments, reactions, and time entries without proper permission verification.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","score":5.3},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","score":4.3},"cwes":["CWE-863"],"references":["https://github.com/go-vikunja/vikunja/security/advisories/GHSA-9rg3-v78m-26q8","https://www.vulncheck.com/advisories/vikunja-before-2.6.0-api-token-scope-bypass-via-expand-parameter","https://github.com/go-vikunja/vikunja/security/advisories/GHSA-9rg3-v78m-26q8"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:53:43.293028046+00:00"},"epss":{"cve":"CVE-2026-91983","score":0.00305,"percentile":0.23303,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-9rg3-v78m-26q8","url":"https://osv.dev/vulnerability/GHSA-9rg3-v78m-26q8","summary":"Vikunja: API token scopes bypassed via task expand parameter (comments, reactions, time entry counts)","modified":"2026-10-19T21:41:16.622292055Z","packages":[{"ecosystem":"Go","name":"code.vikunja.io/api","purl":"pkg:golang/code.vikunja.io/api","ranges":[">=1.0.0 <2.6.0"],"fixed":["2.6.0"]}]},{"id":"GO-2026-6726","url":"https://osv.dev/vulnerability/GO-2026-6726","summary":"Vikunja: API token scopes bypassed via task expand parameter (comments, reactions, time entry counts) in code.vikunja.io/api","modified":"2026-10-19T21:31:52.830337014Z","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."]}