Vulnerability in Parse-Community Parse-Server

CVE-2026-31901

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 8.6.34 and 9.6.0-alpha.8, the email verification endpoint (/verificationEmailRequest) returns distinct error responses depending on whether an email address belongs to an existing user, is already verified, or does not exist. An attacker can send requests with different email addresses and observe the error codes to determine which email addresses are registered in the application. This is a user enumeration vulnerability that affects any Parse Server deployment with email verification enabled (verifyUserEmails: true). This vulnerability is fixed in 8.6.34 and 9.6.0-alpha.8.

EPSS: 0.002 (15.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-31901?
CVE-2026-31901 is a medium-severity vulnerability in Parse-Community Parse-Server, classified under Observable Response Discrepancy. CVSS score: 5.3/10. Published 2026-03-11.
How severe is CVE-2026-31901?
Medium severity. CVSS v3 base score is 5.3 out of 10.