Vulnerability · Published Mar 30, 2026 · Assigned by GitHub_M

CVE-2026-31946OpenOLAT: Authentication bypass via forged JWT in OIDC implicit flow

Critical 9.8

In plain English

A critical-severity improper authentication in OpenOLAT from OpenOLAT. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 11% of all known vulnerabilities).

Severity (CVSS 3.1)9.8Critical

Exploit odds (30 days)0.2%top 88.7% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

Vendor	Product	Versions
OpenOLAT	OpenOLAT	>= 10.5.4, < 20.2.5

Weakness: CWE-287, CWE-347 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

https://github.com/OpenOLAT/OpenOLAT/security/advisories/GHSA-v8vp-x4q4-2vch x_refsource_CONFIRM