CVE-2026-97637

JSON API Auth <= 3.1.2 - Unauthenticated Authentication Bypass via Cached 'generate_auth_cookie' Response

2026-10-01 19:01
Chi Trung Huynh

Strategic Overview

Status
Patched in 3.1.3
Affected Plugin
JSON API Auth
Affected Version
<= 3.1.2
CVSS
9.8Critical
Weakness type
CWE-287 · Improper Authentication
CVE
CVE-2026-97637
View all JSON API Auth vulnerabilities

At a glance

CVE-2026-97637 is a critical-severity Improper Authentication vulnerability in the JSON API Auth WordPress plugin, affecting versions <= 3.1.2. It carries a CVSS score of 9.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires no authentication. The issue is fixed in version 3.1.3; sites on affected versions should update now. Disclosed October 2026, reported by Chi Trung Huynh.

Vulnerability Overview

The JSON API Auth plugin for WordPress is vulnerable to Authentication Bypass via Cached Session Cookie Disclosure in all versions up to, and including, 3.1.2. The vulnerability exists because the required PI-Media/json-api parent plugin caches controller dispatch results in transients keyed solely by URI and query string, ignoring HTTP method and POST body; this causes the `generate_auth_cookie()` endpoint — which embeds a live WordPress `logged_in` cookie produced by `wp_generate_auth_cookie()` directly in its JSON response body — to serve that cached authenticated response to any subsequent unauthenticated GET request to the same URI. This makes it possible for unauthenticated attackers to retrieve a valid Administrator `logged_in` session cookie from the cached response and use it to fully authenticate as the site Administrator, including via the same plugin's `get_currentuserinfo` endpoint and any cookie-authenticated controller action. Exploitation requires the PI-Media/json-api parent plugin to be installed and active with the Auth controller enabled, and a legitimate Administrator must have POSTed to `/api/auth/generate_auth_cookie/` within the preceding 24-hour cache TTL; the nominal HTTPS enforcement gate present in `Auth.php` is trivially bypassed by supplying `insecure=cool` as a request parameter.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site, and no interaction from a victim user. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.

CWE-287: Improper Authentication

JSON API Auth <= 3.1.2 carries this weakness at generate_auth_cookie(), and reaching it takes no account at all. Improper authentication means the mechanism that proves who a caller is can be satisfied without the secret it was supposed to require.

An attacker authenticates as another user — administrators included — without ever knowing a password, so password policies and login rate limits never come into play. For JSON API Auth the fix is 3.1.3: builds <= 3.1.2 are affected, anything from 3.1.3 onward is not.

Remediation

Update to version 3.1.3, or a newer patched version

How does WordSec protect against this?

This one needs no account at all, which puts it outside what login hardening can reach; WordSec's login security narrows the account-level paths around it, and the firewall is what inspects the request itself. None of that substitutes for the fix: JSON API Auth 3.1.3 closes this, and updating the plugin is the step that ends it.

  • Login Security
  • Alerts

External References

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