# CVE-2026-111898: phpMyFAQ authentication bypass in Keycloak account linking

Source: https://junglewise.ai/threats/cve-2026-111898-phpmyfaq-4-2-0-alpha-before-4-2-0-beta-contains-an  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-17. Updated: 2026-10-17  
License: CC BY 4.0 with a link back

CVE-2026-111898 · Severity: high · CVSS 7.5 · Published 2026-10-17

phpMyFAQ is a frequently asked questions (FAQ) knowledge base application. An authentication flaw in its Keycloak integration allows attackers with a Keycloak account matching an existing local username or email to take over that local account, potentially gaining full administrative access. The vulnerability requires an attacker to control or obtain credentials from a Keycloak identity provider and does not require the matched email to be verified.

Technologies: [Thorsten phpMyFAQ](https://junglewise.ai/threats/technologies/phpmyfaq). Vendors: [Thorsten](https://junglewise.ai/threats/vendors/thorsten).

## Quick answers

**Is CVE-2026-111898 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-111898 being exploited in the wild.

**How severe is CVE-2026-111898?** High severity, with a CVSS score of 7.5, published 17 October 2026.

**Which products and versions are affected?** Thorsten phpMyFAQ 4.2.0-alpha.2 before 4.2.0-beta.

**Is there a fix for CVE-2026-111898?** Yes: fixed in 4.2.0-beta. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-111898 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-111898?** Check whether you run Thorsten phpMyFAQ at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 4.2.0-beta

## Technical details

The KeycloakAuthenticationController::resolveLocalLogin() method performs implicit account linking without verifying authorization: it first checks for an existing keycloak_sub binding, then falls back to matching preferred_username or email against existing local accounts. When no binding exists for a matched account, the attacker's Keycloak subject is stored and authenticated. The email-based matching does not require an email_verified claim, enabling account takeover even with unverified identities. Attack vector is network-based, requires low privileges in Keycloak, and occurs at the /auth/keycloak/authorize endpoint.

## Affected products

- thorsten phpMyFAQ 4.2.0-alpha.2 before 4.2.0-beta

## Timeline

- 2026-10-03: disclosed: GitHub Security Advisory GHSA-rg4w-2j3r-2hhp published
- 2026-10-17: advisory: CVE-2026-111898 and NVD advisory published

## References

- [https://github.com/thorsten/phpMyFAQ/security/advisories/GHSA-rg4w-2j3r-2hhp](https://github.com/thorsten/phpMyFAQ/security/advisories/GHSA-rg4w-2j3r-2hhp)
- [https://www.vulncheck.com/advisories/phpmyfaq-4.2.0-alpha-before-4.2.0-beta-account-takeover-via-keycloak-implicit-account-linking](https://www.vulncheck.com/advisories/phpmyfaq-4.2.0-alpha-before-4.2.0-beta-account-takeover-via-keycloak-implicit-account-linking)

## Related threats

- [phpMyFAQ insufficient authorization in group deletion](https://junglewise.ai/threats/cve-2026-124433-phpmyfaq-before-4-1-11-contains-an-insufficient-authorization)
- [phpMyFAQ WebAuthn account enumeration in prepare-login](https://junglewise.ai/threats/cve-2026-124432-phpmyfaq-4-1-9-before-4-1-11-and-4-2-0-pre-releases-before-4-2-0)
- [phpMyFAQ authorization bypass in attachment downloads](https://junglewise.ai/threats/cve-2026-111910-phpmyfaq-before-4-1-9-and-4-2-0-alpha-before-4-2-0-beta-contains)
- [phpMyFAQ missing authorization in deleteUser API](https://junglewise.ai/threats/cve-2026-111909-phpmyfaq-before-4-1-9-contains-a-missing-authorization)
- [phpMyFAQ broken object-level authorization in FAQ update API](https://junglewise.ai/threats/cve-2026-111908-phpmyfaq-4-0-0-before-4-1-9-and-4-2-0-alpha-before-4-2-0-beta)