Auth bypass in Parse-Community Parse-Server

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.

Vulnerability class: Broken Authentication

EPSS: 0.004 (34.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-30949?
CVE-2026-30949 is a high-severity vulnerability in Parse-Community Parse-Server, classified under Improper Authentication. CVSS score: 8.8/10. Published 2026-03-10.
How severe is CVE-2026-30949?
High severity. CVSS v3 base score is 8.8 out of 10.