# CVE-2026-81888

## Summary

- **CVE ID:** CVE-2026-81888
- **Severity:** MEDIUM
- **CVSS Score:** 5.4 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N)
- **CWE:** CWE-352, CWE-1275
- **Published:** Aug 31, 2026
- **Last Modified:** Sep 1, 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.

## Affected Products

- honojs — @hono/oauth-providers (< 0.8.6)

## References

- [CNA](https://github.com/honojs/middleware/security/advisories/GHSA-fm3f-ch8h-qw8q)
- [CNA](https://github.com/honojs/middleware/pull/2040)
- [CNA](https://github.com/honojs/middleware/commit/b37765f40b7bddb1d8fce39573b085222dea58c1)
- [CNA](https://github.com/honojs/middleware/releases/tag/%40hono%2Foauth-providers%400.8.6)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.15%
- **EPSS Percentile:** 4.4

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._