CVE-2026-18639

Velociraptor OIDC Authenticator susceptible to email spoofing

Published Aug 11, 2026 CVSS 3.1 · 7.3 High EPSS < 1% KEV · Not listed
Description
When Velociraptor is configured to use an OIDC IdP for authentication, it uses the email claim as a username. However, some IdP allow users to change the email claim without verification. Some IdPs do not set the "email_verified" claim and do not actually verify the email.

This allows a user to impersonate another user by setting their email address within the IdP, allowing account takeover.

Remediation

Vendor Workaround

You can change the claim that Velociraptor uses as the username using the  Configuration File https://docs.velociraptor.app/docs/deployment/references/#GUI.authenticator.claims.username  . Set the username using a more permanent claim for example with Azure the "upn" or "oid" can not be chosen by the user.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Rapid7
Rapid7 velociraptor
Vendors & Products Rapid7
Rapid7 velociraptor
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description When Velociraptor is configured to use an OIDC IdP for authentication, it uses the email claim as a username. However, some IdP allow users to change the email claim without verification. Some IdPs do not set the "email_verified" claim and do not actually verify the email. This allows a user to impersonate another user by setting their email address within the IdP, allowing account takeover.
Title Velociraptor OIDC Authenticator susceptible to email spoofing
Weaknesses CWE-290
References
Metrics cvssV3_1

{'score': 7.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
rapid7
Published
Updated
Aug 11, 2026, 5:14 PM
Reserved
Aug 3, 2026, 10:45 AM
Status
Awaiting Analysis
Published
Aug 11, 2026, 4:17 PM
Modified
Oct 23, 2026, 7:10 PM