CVE-2026-18639
Velociraptor OIDC Authenticator susceptible to email spoofing
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.
INFO
Published Date :
Aug. 11, 2026, 4:17 p.m.
Last Modified :
Aug. 11, 2026, 6:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | 9974b330-7714-4307-a722-5648477acda7 | ||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 3.1 | HIGH | MITRE-CVE |
Solution
- Configure IdP to enforce email verification.
- Validate 'email_verified' claim if provided.
- Ensure email uniqueness in Velociraptor.
- Consider alternative unique identifiers.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-18639.
| URL | Resource |
|---|---|
| http://docs.velociraptor.app/announcements/advisories/cve-2026-18639/ |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-18639 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-18639
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-18639 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-18639 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 11, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-18639', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-11T17:13:54.338948Z'} -
New CVE Received by [email protected]
Aug. 11, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://github.com/Velocidex/velociraptor/', 'vendor': 'Rapid7', 'product': 'Velociraptor', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '0.77.2', 'versionType': 'semver'}], 'defaultStatus': 'unaffected'}] 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. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N Added CWE CWE-290 Added Reference http://docs.velociraptor.app/announcements/advisories/cve-2026-18639/