CVE-2026-31946

Critical

Description

OpenOlat is an open source web-based e-learning platform for teaching, learning, assessment and communication. From version 10.5.4 to before version 20.2.5, OpenOLAT's OpenID Connect implicit flow implementation does not verify JWT signatures. The JSONWebToken.parse() method silently discards the signature segment of the compact JWT (header.payload.signature), and the getAccessToken() methods in both OpenIdConnectApi and OpenIdConnectFullConfigurableApi only validate claim-level fields (issuer, audience, state, nonce) without any cryptographic signature verification against the Identity Provider's JWKS endpoint. This issue has been patched in version 20.2.5.

SeverityCritical

CVSS9.8

Exploit probability—

ProductFrentix Openolat

PublishedMar 30, 2026

First seenMar 30, 2026

Weakness typeCWE-287Improper authentication CWE-347CWE-347

How to fix

Update

frentix openolat20.2.5 or later

Affected products

Product	Affected versions	Fixed in
frentix openolat	10.5.4 ≤ v < 20.2.5	20.2.5

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