Vulnerability in Parse-Community Parse-Server

CVE-2026-33323

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.51 and 9.6.0-alpha.40, the Pages route and legacy PublicAPI route for resending email verification links return distinguishable responses depending on whether the provided username exists and has an unverified email. This allows an unauthenticated attacker to enumerate valid usernames by observing different redirect targets. The existing emailVerifySuccessOnInvalidEmail configuration option, which is enabled by default and protects the API route against this, did not apply to these routes. This issue has been patched in versions 8.6.51 and 9.6.0-alpha.40.

EPSS: 0.003 (24.7th 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-2026-33323?
CVE-2026-33323 is a medium-severity vulnerability in Parse-Community Parse-Server, classified under Observable Response Discrepancy. CVSS score: 5.3/10. Published 2026-03-24.
How severe is CVE-2026-33323?
Medium severity. CVSS v3 base score is 5.3 out of 10.