{"id":"CVE-2026-62367","state":"PUBLISHED","title":"Vikunja: OIDC email-fallback account linking ignores email_verified, enabling local-account takeover","description":"Vikunja is an open-source self-hosted task management platform. In versions 1.0.0 through 2.3.0, when an administrator enables the per-provider `emailfallback` option on an OpenID Connect provider, Vikunja links an SSO login to a pre-existing local (username+password) account using only the `email` claim from the IdP. The fallback never checks an `email_verified` (or Microsoft `xms_edov`) signal and never requires the matched account's password. An attacker who can obtain a token from the configured issuer carrying a victim's email logs in as that victim with a full session, with no consent or interaction from the victim. Version 2.4.0 fixes the issue.","publishedAt":"2026-10-09T20:49:08.891Z","updatedAt":"2026-10-13T20:25:26.027Z","severity":{"score":7.5,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["go-vikunja vikunja"],"affected":[{"vendor":"go-vikunja","product":"vikunja","versions":[{"version":">= 1.0.0, < 2.4.0","status":"affected"}]}],"references":["https://github.com/go-vikunja/vikunja/security/advisories/GHSA-xv7q-fvmc-jx96","https://github.com/go-vikunja/vikunja/commit/7854f2729ab72000210b61c25929678fd6901630","https://github.com/go-vikunja/vikunja/releases/tag/v2.4.0"],"weaknesses":["CWE-287","CWE-290","CWE-345"],"ingestedAt":"2026-10-29T20:12:32.778Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/62xxx/CVE-2026-62367.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-62367","state":"PUBLISHED","datePublished":"2026-10-09T20:49:08.891Z","dateUpdated":"2026-10-13T20:25:26.027Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-07-13T22:04:59.677Z"},"containers":{"cna":{"title":"Vikunja: OIDC email-fallback account linking ignores email_verified, enabling local-account takeover","descriptions":[{"lang":"en","value":"Vikunja is an open-source self-hosted task management platform. In versions 1.0.0 through 2.3.0, when an administrator enables the per-provider `emailfallback` option on an OpenID Connect provider, Vikunja links an SSO login to a pre-existing local (username+password) account using only the `email` claim from the IdP. The fallback never checks an `email_verified` (or Microsoft `xms_edov`) signal and never requires the matched account's password. An attacker who can obtain a token from the configured issuer carrying a victim's email logs in as that victim with a full session, with no consent or interaction from the victim. Version 2.4.0 fixes the issue."}],"affected":[{"vendor":"go-vikunja","product":"vikunja","versions":[{"version":">= 1.0.0, < 2.4.0","status":"affected"}]}],"references":[{"url":"https://github.com/go-vikunja/vikunja/security/advisories/GHSA-xv7q-fvmc-jx96","name":"https://github.com/go-vikunja/vikunja/security/advisories/GHSA-xv7q-fvmc-jx96","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/go-vikunja/vikunja/commit/7854f2729ab72000210b61c25929678fd6901630","name":"https://github.com/go-vikunja/vikunja/commit/7854f2729ab72000210b61c25929678fd6901630","tags":["x_refsource_MISC"]},{"url":"https://github.com/go-vikunja/vikunja/releases/tag/v2.4.0","name":"https://github.com/go-vikunja/vikunja/releases/tag/v2.4.0","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"LOCAL","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":7.5,"baseSeverity":"HIGH","vectorString":"CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-287","lang":"en","description":"CWE-287: Improper Authentication","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-290","lang":"en","description":"CWE-290: Authentication Bypass by Spoofing","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-345","lang":"en","description":"CWE-345: Insufficient Verification of Data Authenticity","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-10-09T20:49:08.891Z"},"source":{"advisory":"GHSA-xv7q-fvmc-jx96","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-13T20:14:20.538444Z","id":"CVE-2026-62367","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":"2026-10-13T20:25:26.027Z"}}]}}}