Auth bypass in Nhost

CVE-2026-41574

Nhost is an open source Firebase alternative with GraphQL. Prior to version 0.49.1, Nhost automatically links an incoming OAuth identity to an existing Nhost account when the email addresses match. This is only safe when the email has been verified by the OAuth provider. Nhost's controller trusts a profile.EmailVerified boolean that is set by each provider adapter. The vulnerability is that several provider adapters do not correctly populate this field they either silently drop a verified field the provider API actually returns (Discord), or they fall back to accepting unconfirmed emails and marking them as verified (Bitbucket). Two Microsoft providers (AzureAD, EntraID) derive the email from non-ownership-proving fields like the user principal name, then mark it verified. The result is that an attacker can present an email they don't own to Nhost, have the OAuth identity merged into the victim's account, and receive a full authenticated session. This issue has been patched in version 0.49.1.

Vulnerability class: Broken Authentication

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.009 (58.4th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 58th percentile — 58.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-41574: held from 0.008 to 0.009.

EPSS over last 30 days · oldest: 0.008 · newest: 0.009 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-41574?
CVE-2026-41574 is a critical-severity vulnerability in Nhost, classified under Improper Authentication. CVSS score: 9.8/10. Published 2026-05-08.
How severe is CVE-2026-41574?
Critical severity. CVSS v3 base score is 9.8 out of 10.