CVE-2026-110008

@fastify/oauth2 is a Fastify wrapper for OAuth2 login flows. In versions 7.2.0 through 8.3.1, the state and code-verifier cookies are set without a Path attribute at a login route with two or more path segments, while the clearing step at the OAuth callback writes them with a root path, so the original cookies survive the callback and the documented single-use guarantee for the state value does not hold. A state value an attacker learns stays valid for the rest of the browser session, letting the attacker drive their own authorization flow in the victim's browser and sign the victim in to the attacker's account (login CSRF). The issue is fixed in @fastify/oauth2 8.3.2, and users should upgrade to 8.3.2 or later. As a workaround, set an explicit cookie path so the set and the clear name the same cookie.

CVSS v3 4.2 MEDIUM

4.2^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.6 / Impact : 2.5

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://cna.openjsf.org/security-advisories.html
https://github.com/fastify/fastify-oauth2/security/advisories/GHSA-7fcr-mwg4-pw9q

Configurations

No configuration.

History

19 Oct 2026, 14:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-19 14:16

Updated : 2026-10-19 21:13

NVD link : CVE-2026-110008

Mitre link : CVE-2026-110008

CVE.ORG link : CVE-2026-110008

JSON object : View

Products Affected

No product.

CWE

CWE-352

Cross-Site Request Forgery (CSRF)

CWE-459

Incomplete Cleanup

CWE-613

Insufficient Session Expiration

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