CVE-2026-31901

Description

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, 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.

How to fix CVE-2026-31901

To remediate CVE-2026-31901, upgrade the affected package to a fixed version below.

• —upgrade to 8.6.34 or later
• —upgrade to 9.6.0-alpha.8 or later

Is CVE-2026-31901 being exploited?

Low — EPSS is 0.2%, meaning exploitation activity has not been observed at scale.

Affected packages (2)

• from 0, < 8.6.34, >= 9.0.0, < 9.6.0
• >= 9.0.0-alpha.1, < 9.6.0-alpha.8

CVSS scores

References (5)

• ADVISORYnvd.nist.gov/vuln/detail/CVE-2026-31901
• PATCHgithub.com/parse-community/parse-server
• WEBgithub.com/parse-community/parse-server/releases/tag/8.6.34
• WEBgithub.com/parse-community/parse-server/releases/tag/9.6.0-alpha.8