CVE-2026-54599 Wallos: OIDC state parameter never validated — login CSRF / account takeover
Attackers can force victims to log into attacker-controlled accounts via OIDC callback due to missing state validation, leading to account takeover.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-54599?
CVE-2026-54599 is a high-severity vulnerability in ellite Wallos, published on 31 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
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.
Weakness: CWE-352
Which versions are affected by CVE-2026-54599?
How do I fix CVE-2026-54599?
No fix has been published for CVE-2026-54599 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-54599 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-54599 exists.
Sources
Also known as GHSA-gr2w-m9v4-qm3v.