{"schemaVersion":3,"id":"CVE-2026-91985","aliases":["GHSA-qfwc-vx6f-3g6g","GO-2026-6747"],"status":"published","duplicateOf":null,"title":null,"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.","dates":{"published":"2026-09-15T15:18:28.282Z","modified":"2026-09-15T16:04:15.007Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":8.7,"severity":"high","version":"4.0","versionLabel":"v4.0","source":"CVE.org","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","computed":false,"selection":"backend-summary"},"metrics":[{"version":"4.0","versionLabel":"v4.0","source":"CVE.org","score":8.7,"severity":"high","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","exploitability":null,"impact":null,"computed":false},{"version":"3.1","versionLabel":"v3.1","source":"CVE.org","score":7.5,"severity":"high","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","exploitability":null,"impact":null,"computed":false},{"version":"4.0","versionLabel":"v4.0","source":"NVD","score":8.7,"severity":"high","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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","exploitability":null,"impact":null,"computed":false},{"version":"3.1","versionLabel":"v3.1","source":"NVD","score":7.5,"severity":"high","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","exploitability":null,"impact":null,"computed":false}]},"epss":{"probability":0.00432,"percentile":0.36407,"severity":"low","asOf":"2026-10-21T00:00:00.000Z","change":{"pp":0.051000000000000004,"baselineDate":"2026-09-21T00:00:00.000Z","baselineScore":0.00381},"history":[{"date":"2026-09-16T00:00:00.000Z","score":0.00381,"percentile":null},{"date":"2026-09-17T00:00:00.000Z","score":0.00381,"percentile":null},{"date":"2026-09-18T00:00:00.000Z","score":0.00381,"percentile":null},{"date":"2026-09-19T00:00:00.000Z","score":0.00381,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.00381,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.00381,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.00381,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.00381,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-20T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-21T00:00:00.000Z","score":0.00432,"percentile":0.36407}],"last30":[{"date":"2026-09-21T00:00:00.000Z","score":0.00381,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.00381,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.00381,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-20T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-10-21T00:00:00.000Z","score":0.00432,"percentile":0.36407}]},"kev":{"state":"not-listed","entries":[],"listedCount":0,"totalCatalogs":3,"catalogs":[{"source":"cisa","label":"CISA","listed":false,"entry":null},{"source":"enisa","label":"ENISA","listed":false,"entry":null},{"source":"circl","label":"CIRCL","listed":false,"entry":null}]},"ransomware":{"state":"none-recorded","sources":[]},"exploits":[],"exploitCount":0,"weaknesses":[{"id":"CWE-200","name":"Exposure of Sensitive Information to an Unauthorized Actor","description":"The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.","type":"weakness","status":"Draft","abstraction":"Class","likelihoodOfExploit":"High","url":"https://cwe.mitre.org/data/definitions/200.html"}],"affected":[{"vendor":"go-vikunja","product":"vikunja","name":"vikunja","label":"vikunja","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"< 2.6.0","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 2.6.0","eol":null,"hubHref":"/vendor/go-vikunja/vikunja"},{"vendor":"code.vikunja.io","product":"api","name":"code.vikunja.io/api","label":"api","ecosystem":"Go","cpePart":null,"purl":"pkg:golang/code.vikunja.io/api","purlType":"golang","versions":[{"text":"< 2.6.0","noFixRecorded":false,"fixedIn":null},{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"< 2.6.0 | All versions (No fix recorded)","eol":null,"hubHref":null}],"affectedCount":2,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://github.com/go-vikunja/vikunja/security/advisories/GHSA-qfwc-vx6f-3g6g","label":"github.com/go-vikunja/vikunja/security/advisories/GHSA-qfwc-vx6f-3g6g","hostname":"github.com","tags":["Vendor Advisory","WEB","Advisory"]},{"url":"https://www.vulncheck.com/advisories/vikunja-before-2.6.0-privilege-escalation-via-link-share-hash","label":"www.vulncheck.com/advisories/vikunja-before-2.6.0-privilege-escalation-via-link-share-hash","hostname":"www.vulncheck.com","tags":["Third Party Advisory","WEB"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-91985","label":"nvd.nist.gov/vuln/detail/CVE-2026-91985","hostname":"nvd.nist.gov","tags":["Advisory"]},{"url":"https://github.com/go-vikunja/vikunja/pull/3688","label":"github.com/go-vikunja/vikunja/pull/3688","hostname":"github.com","tags":["WEB"]},{"url":"https://github.com/go-vikunja/vikunja/commit/077dc4de79ce6f1ab59215a2c7bf9b30423685f2","label":"github.com/go-vikunja/vikunja/commit/077dc4de79ce6f1ab59215a2c7bf9b30423685f2","hostname":"github.com","tags":["WEB"]},{"url":"https://github.com/go-vikunja/vikunja","label":"github.com/go-vikunja/vikunja","hostname":"github.com","tags":["PACKAGE"]},{"url":"https://github.com/go-vikunja/vikunja/releases/tag/v2.6.0","label":"github.com/go-vikunja/vikunja/releases/tag/v2.6.0","hostname":"github.com","tags":["WEB"]}],"lineage":{"upstream":[],"downstream":[],"duplicates":[],"related":[]},"timeline":[{"kind":"published","date":"2026-09-15T15:18:28.282Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2026-09-15T16:04:15.007Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":35,"level":"medium","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-22T10:18:19.257Z","stale":false,"partial":false}}