Insufficient verification of data authenticity in Parse Server - CVE-2026-27804
Published: April 6, 2026
Vulnerability identifier: #VU124967
CSH Severity: High
CVSS v4: 9.3 [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]
CVE-ID: CVE-2026-27804
CWE-ID: CWE-345
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to log in as any user linked to a Google account.
The vulnerability exists due to insufficient verification of data authenticity in the Google auth adapter when processing forged Google authentication tokens. A remote attacker can forge a token with alg set to none to log in as any user linked to a Google account.
Only deployments with Google authentication enabled are vulnerable.
Affected software
Parse Server
How to mitigate CVE-2026-27804
Install security update from vendor's website.
Parse Server - addressed in versions 8.6.3, 9.3.1 alpha.4