CVE-2026-25519 OpenSlides has incorrect access control vulnerability in authentication service

High 8.1 Published 4 Feb 2026 Updated 4 Feb 2026

Attackers can bypass authentication for SAML-synced users by using a trivial password, allowing unauthorized access to the assembly system.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-25519?

CVE-2026-25519 is a high-severity authentication bypass vulnerability in OpenSlides, published on 4 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

OpenSlides is a free, web based presentation and assembly system for managing and projecting agenda, motions and elections of an assembly. Prior to version 4.2.29, OpenSlides supports local logins with username and password or an optionally configurable single sign on with SAML via an external IDP. For users synced to OpenSlides via an external IDP, there is an incorrect access control regarding the local login of these users. Users can successfully login using the local login form and the OpenSlides username of a SAML user and a trivial password. This password is valid for all SAML users. This issue has been patched in version 4.2.29.

Weakness: CWE-284

Which versions are affected by CVE-2026-25519?

It affects 1 product.

Products include Openslides Openslides.

How do I fix CVE-2026-25519?

No fix has been published for CVE-2026-25519 yet. Limit exposure of the affected software until one is available.

Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.

Is CVE-2026-25519 being exploited?

There is no known exploitation of CVE-2026-25519 in the wild and no public exploit code.

Sources

Also known as GHSA-vv4h-8wfc-pf8c.