Parse Server email verification resend page leaks user existence

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

6.3 · CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2026-33323: 0.34% estimated exploitation activity in the next 30 days; percentile 26.99 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact 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. Patches The email verification resend routes now respect the emailVerifySuccessOnInvalidEmail option. When set to true (the default), both routes redirect to the success page regardless of the outcome, preventing user enumeration. Workarounds There is no known workaround to prevent the information disclosure other than upgrading.

Published by the source

19 Mar 2026, 18:21 UTC

Last modified by the source

30 Mar 2026, 14:05 UTC

Source last checked

26 Oct 2026, 12:47 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-h29g-q5c2-9h4f

2. Revision 2 · amended · 24 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-h29g-q5c2-9h4f

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-33323

Advisory: Parse Server email verification resend page leaks user existence
IDs: CVE-2026-33323, GHSA-h29g-q5c2-9h4f
Record: https://patchnext.com/advisories/cve-2026-33323 (revision 3, source checked 26 Oct 2026, 12:47 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: parse-server 9.6.0-alpha.40, 8.6.51. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm parse-server: affected >= 9.0.0, < 9.6.0-alpha.40; < 8.6.51; fixed in 9.6.0-alpha.40, 8.6.51

## Suggested inspection (read-only)
- `npm ls parse-server --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on parse-server.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-h29g-q5c2-9h4f (OSV record GHSA-h29g-q5c2-9h4f lists affected ranges: npm parse-server >=9.0.0 =0 <8.6.51 (fixed))
- Verified: https://github.com/advisories/GHSA-h29g-q5c2-9h4f (GitHub-reviewed advisory GHSA-h29g-q5c2-9h4f lists affected ranges: npm parse-server >=9.0.0 =0 <8.6.51)

Commands are suggestions: review each one before running it.