{"cve":"CVE-2026-27804","nvd":{"published":"2026-02-26T00:16:25.793","modified":"2026-06-17T10:27:42.760","status":"Analyzed","description":"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.","cvss_v4":{"vector":"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","score":9.3},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","score":9.1},"cwes":["CWE-327","CWE-345"],"references":["https://github.com/parse-community/parse-server/commit/9b94083accb7f3e72c6b8126c195c7a03dd2dfd7","https://github.com/parse-community/parse-server/commit/9d5942d50e55c822924c27b05aa98f1393e7a330","https://github.com/parse-community/parse-server/releases/tag/8.6.3","https://github.com/parse-community/parse-server/releases/tag/9.3.1-alpha.4","https://github.com/parse-community/parse-server/security/advisories/GHSA-4q3h-vp4r-prv2"],"products":["parseplatform:parse-server"],"source":"nvd","synced_at":"2026-10-19T22:24:17.937441719+00:00"},"epss":{"cve":"CVE-2026-27804","score":0.00201,"percentile":0.09994,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-4q3h-vp4r-prv2","url":"https://osv.dev/vulnerability/GHSA-4q3h-vp4r-prv2","summary":"Parse Server: Account takeover via JWT algorithm confusion in Google auth adapter","modified":"2026-03-02T12:17:22.300541Z","packages":[{"ecosystem":"npm","name":"parse-server","purl":"pkg:npm/parse-server","ranges":[">=9.0.0 <9.3.1-alpha.4"],"fixed":["9.3.1-alpha.4"]},{"ecosystem":"npm","name":"parse-server","purl":"pkg:npm/parse-server","ranges":["<8.6.3"],"fixed":["8.6.3"]}]}],"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."]}