CVE-2026-54599

What it is

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.

At a glance

Exploitability

Can be exploited over the network without logging in, but needs a user to act. High risk of data exposure, data tampering, service disruption.

Exploit odds

0.2% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-08-31 21:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-09-08 21:11 UTC Last updatedMost recent change to the record

Details

Published

2026-08-31 21:17 UTC

Last modified

2026-09-08 21:11 UTC

Exploit probability

0.2% · EPSS, next 30 days

Weakness

CWE-352 · Cross-site request forgery

Record status

Deferred

Attack profile CVSS 4.0 · 7.5

Attack vector

Network

Complexity

Low

Attack requirements

Present

Privileges needed

None

User interaction

Active

Confidentiality

High

Integrity

High

Availability

High