Observable Response Discrepancy in Parse Server - CVE-2026-31901
Published: April 6, 2026
Vulnerability identifier: #VU124998
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-31901
CWE-ID: CWE-204
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to disclose sensitive information.
The vulnerability exists due to observable response discrepancy in the /verificationEmailRequest endpoint when handling email verification requests. A remote attacker can send requests with different email addresses and observe distinct error responses to disclose sensitive information.
Only deployments with email verification enabled (verifyUserEmails: true) are vulnerable.
Affected software
Parse Server
How to mitigate CVE-2026-31901
Install security update from vendor's website.
Parse Server - addressed in versions 8.6.34, 9.6.0 alpha.8