{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-27804","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-02-24T02:31:33.266Z","datePublished":"2026-02-25T23:48:20.858Z","dateUpdated":"2026-02-26T17:03:50.903Z"},"containers":{"cna":{"title":"Parse Server: Account takeover via JWT algorithm confusion in Google auth adapter","problemTypes":[{"descriptions":[{"cweId":"CWE-327","lang":"en","description":"CWE-327: Use of a Broken or Risky Cryptographic Algorithm","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-345","lang":"en","description":"CWE-345: Insufficient Verification of Data Authenticity","type":"CWE"}]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":9.3,"baseSeverity":"CRITICAL","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N","version":"4.0"}}],"references":[{"name":"https://github.com/parse-community/parse-server/security/advisories/GHSA-4q3h-vp4r-prv2","tags":["x_refsource_CONFIRM"],"url":"https://github.com/parse-community/parse-server/security/advisories/GHSA-4q3h-vp4r-prv2"},{"name":"https://github.com/parse-community/parse-server/commit/9b94083accb7f3e72c6b8126c195c7a03dd2dfd7","tags":["x_refsource_MISC"],"url":"https://github.com/parse-community/parse-server/commit/9b94083accb7f3e72c6b8126c195c7a03dd2dfd7"},{"name":"https://github.com/parse-community/parse-server/commit/9d5942d50e55c822924c27b05aa98f1393e7a330","tags":["x_refsource_MISC"],"url":"https://github.com/parse-community/parse-server/commit/9d5942d50e55c822924c27b05aa98f1393e7a330"},{"name":"https://github.com/parse-community/parse-server/releases/tag/8.6.3","tags":["x_refsource_MISC"],"url":"https://github.com/parse-community/parse-server/releases/tag/8.6.3"},{"name":"https://github.com/parse-community/parse-server/releases/tag/9.3.1-alpha.4","tags":["x_refsource_MISC"],"url":"https://github.com/parse-community/parse-server/releases/tag/9.3.1-alpha.4"}],"affected":[{"vendor":"parse-community","product":"parse-server","versions":[{"version":">= 9.0.0, < 9.3.1-alpha.4","status":"affected"},{"version":"< 8.6.3","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-02-25T23:48:20.858Z"},"descriptions":[{"lang":"en","value":"Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.3 and 9.1.1-alpha.4, an unauthenticated attacker can forge a Google authentication token with `alg: \"none\"` to log in as any user linked to a Google account, without knowing their credentials. All deployments with Google authentication enabled are affected. The fix in versions 8.6.3 and 9.1.1-alpha.4 hardcodes the expected `RS256` algorithm instead of trusting the JWT header, and replaces the Google adapter's custom key fetcher with `jwks-rsa` which rejects unknown key IDs. As a workaround, dsable Google authentication until upgrading is possible."}],"source":{"advisory":"GHSA-4q3h-vp4r-prv2","discovery":"UNKNOWN"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-02-26T17:03:17.987949Z","id":"CVE-2026-27804","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-02-26T17:03:50.903Z"}}]}}