CVE-2026-54599: Ellite Wallos

High severity, CVSS 7.5. EPSS: 0.2% chance of exploitation in the next 30 days.

Wallos is an open-source, self-hostable personal subscription tracker. Prior to version 4.9.4, login.php generates an OIDC state nonce stored in $_SESSION['oidc_state'], but checksession.php dispatches the OIDC callback without comparing the incoming state against the session value. An attacker can trick a victim into visiting a crafted URL, causing Wallos to exchange the attacker's authorization code and log the victim into the attacker's account. This issue has been patched in version 4.9.4.

Affected products

• Ellite Wallos: before 4.9.4 (fixed in 4.9.4)

Published 2026-08-31. Last modified 2026-09-08.