Openolat CVEs and Security Vulnerabilities

CVE-2026-31946

OpenOLAT: Authentication bypass via forged JWT in OIDC implicit flow

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.

CVSS 3.1 · 9.8 Critical EPSS < 1% KEV · Not listed

Vendors

Frentix Openolat

Products

Openolat Openolat

CVE-2026-28228

OpenOLAT: Server-Side Template Injection (SSTI) in Velocity templates allows Remote Code Execution

OpenOlat is an open source web-based e-learning platform for teaching, learning, assessment and communication. Prior to versions 19.1.31, 20.1.18, and 20.2.5, an authenticated user with the Author role can inject Velocity directives into a reminder email template. When the reminder is processed (either triggered manually or via the daily cron job), the injected directives are evaluated server-side. By chaining Velocity's #set directive with Java reflection, an attacker can instantiate arbitrary Java classes such as java.lang.ProcessBuilder and execute operating system commands with the privileges of the Tomcat process (typically root in containerized deployments). This issue has been patched in versions 19.1.31, 20.1.18, and 20.2.5.

CVSS 3.1 · 8.8 High EPSS < 1% KEV · Not listed