{"id":"CVE-2026-76216","state":"PUBLISHED","title":"Vikunja through 2.4.0 Principal-Type Confusion via LinkSharing","description":"Vikunja through 2.4.0 contains a principal-type confusion vulnerability where LinkSharing principals with id N are treated as user principals with users.id == N at three permission checks lacking type guards. Attackers with a link-share JWT can remove victims from teams, enumerate and delete victim bot users, or read team rosters by exploiting id collisions in the autoincrement space.","publishedAt":"2026-08-19T14:02:01.282Z","updatedAt":"2026-08-20T16:10:29.192Z","severity":{"score":7.7,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","source":"VulnCheck"},"assigner":"VulnCheck","products":["go-vikunja vikunja"],"affected":[{"vendor":"go-vikunja","product":"vikunja","packageURL":"pkg:golang/code.vikunja.io/api","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"2.4.0","versionType":"semver"}]}],"references":["https://github.com/go-vikunja/vikunja/security/advisories/GHSA-32r8-5843-4qw2","https://www.vulncheck.com/advisories/vikunja-through-principal-type-confusion-via-linksharing"],"weaknesses":["CWE-639"],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/76xxx/CVE-2026-76216.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-76216","state":"PUBLISHED","datePublished":"2026-08-19T14:02:01.282Z","dateUpdated":"2026-08-20T16:10:29.192Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-08-19T11:35:13.689Z"},"containers":{"cna":{"title":"Vikunja through 2.4.0 Principal-Type Confusion via LinkSharing","descriptions":[{"lang":"en","value":"Vikunja through 2.4.0 contains a principal-type confusion vulnerability where LinkSharing principals with id N are treated as user principals with users.id == N at three permission checks lacking type guards. Attackers with a link-share JWT can remove victims from teams, enumerate and delete victim bot users, or read team rosters by exploiting id collisions in the autoincrement space."}],"affected":[{"vendor":"go-vikunja","product":"vikunja","packageURL":"pkg:golang/code.vikunja.io/api","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"2.4.0","versionType":"semver"}]}],"references":[{"url":"https://github.com/go-vikunja/vikunja/security/advisories/GHSA-32r8-5843-4qw2","tags":["vendor-advisory"],"name":"GitHub Security Advisory (GHSA-32r8-5843-4qw2)"},{"url":"https://www.vulncheck.com/advisories/vikunja-through-principal-type-confusion-via-linksharing","name":"VulnCheck Advisory: Vikunja through 2.4.0 Principal-Type Confusion via LinkSharing","tags":["third-party-advisory"]}],"metrics":[{"format":"CVSS","cvssV4_0":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","attackVector":"NETWORK","attackComplexity":"HIGH","attackRequirements":"PRESENT","privilegesRequired":"LOW","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":7.7,"baseSeverity":"HIGH"}},{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH","baseScore":7.5,"baseSeverity":"HIGH"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-639","lang":"en","description":"Authorization Bypass Through User-Controlled Key","type":"CWE"}]}],"providerMetadata":{"shortName":"VulnCheck","orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateUpdated":"2026-08-19T14:02:01.282Z"},"datePublic":"2026-08-04T00:00:00.000Z","cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:vikunja:vikunja:*:*:*:*:*:*:*:*","versionEndIncluding":"2.4.0"}]}]}],"credits":[{"lang":"en","value":"manus-use","type":"reporter"}],"x_generator":{"engine":"vulncheck-endgame"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-20T16:10:21.585796Z","id":"CVE-2026-76216","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-20T16:10:29.192Z"}}]}}}