CVE-2026-81888

@hono/oauth-providers: OAuth state check fails open on omitted state, enabling login CSRF and forced account linking

State: Published
Severity: 5.4 Medium
Published: Aug 31, 2026
Updated: Sep 1, 2026
Reserved: Aug 27, 2026

Description

@hono/oauth-providers is Authentication middleware for Hono. Prior to version 0.8.6, the built-in social login providers accept an OAuth callback even when the `state` value is absent on both sides, so the anti-CSRF check passes for a callback that never came from a genuine login attempt. This defeats the `state`-based CSRF protection under default usage. Version 0.8.6 has a patch.

Scores

CVSS	Score	Vector	Source
3.1	5.4 Medium	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N	GitHub_M

Weaknesses

CWE-352 Cross-Site Request Forgery (CSRF)
CWE-1275 Sensitive Cookie with Improper SameSite Attribute

Affected Products

Product	Versions
@hono/oauth-providershonojs	< 0.8.6Affected

References

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