CVE-2026-30949

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.5.2-alpha.5 and 8.6.18, the Keycloak authentication adapter does not validate the azp (authorized party) claim of Keycloak access tokens against the configured client-id. A valid access token issued by the same Keycloak realm for a different client application can be used to authenticate as any user on the Parse Server that uses the Keycloak adapter. This enables cross-application account takeover in multi-client Keycloak realms. All Parse Server deployments that use the Keycloak authentication adapter with a Keycloak realm that has multiple client applications are affected. This vulnerability is fixed in 9.5.2-alpha.5 and 8.6.18.

• https://github.com/parse-community/parse-server/releases/tag/8.6.18
• https://github.com/parse-community/parse-server/releases/tag/9.5.2-alpha.5
• https://github.com/parse-community/parse-server/security/advisories/GHSA-48mh-j4p5-7j9v