5.4
MEDIUM CVSS 3.1
CVE-2026-81888
@hono/oauth-providers: OAuth state check fails open on omitted state, enabling login CSRF and forced account linking
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.

INFO

Published Date :

Aug. 31, 2026, 9:17 p.m.

Last Modified :

Aug. 31, 2026, 9:17 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-81888 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM [email protected]
CVSS 3.1 MEDIUM MITRE-CVE
Solution
Update @hono/oauth-providers to version 0.8.6 or later to fix CSRF vulnerability.
  • Update @hono/oauth-providers to version 0.8.6 or later.
References to Advisories, Solutions, and Tools
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-81888 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

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-2026-81888 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-81888 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.

  • New CVE Received by [email protected]

    Aug. 31, 2026

    Action Type Old Value New Value
    Added 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.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
    Added CWE CWE-352
    Added CWE CWE-1275
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/81xxx/CVE-2026-81888.json">CVE-2026-81888</a>
    Added Reference https://github.com/honojs/middleware/commit/b37765f40b7bddb1d8fce39573b085222dea58c1
    Added Reference https://github.com/honojs/middleware/pull/2040
    Added Reference https://github.com/honojs/middleware/releases/tag/%40hono%2Foauth-providers%400.8.6
    Added Reference https://github.com/honojs/middleware/security/advisories/GHSA-fm3f-ch8h-qw8q
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.