CVE-2026-31946
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedOpenOlat 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceOpenOlat's OpenID Connect implicit flow implementation does not verify JWT signatures. The JSONWebToken.parse() method discards the signature segment of the JWT, and token validation only checks claim fields (issuer, audience, state, nonce) without cryptographic signature verification against the Identity Provider's JWKS endpoint, allowing attackers to forge valid-looking authentication tokens.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data>= 10.5.4, < 20.2.5CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify OpenOlat installation and versionLocate the OpenOlat installation directory and find the version file or startup banner that displays the version number. Common locations include the application root directory or a version manifest file.Affected if The installed version falls within the range 10.5.4 to 20.2.4 (inclusive), meaning it is less than 20.2.5.
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Verify OpenID Connect is configuredCheck the OpenOlat administration console or configuration files for any OpenID Connect (OIDC) identity provider setups. Look for OIDC implicit flow configurations.Affected if OIDC implicit flow authentication is enabled and configured with an external Identity Provider.
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Confirm OIDC provider uses implicit flowReview the OIDC configuration to determine if the implicit flow is being used. Check for parameters indicating implicit flow rather than authorization code flow.Affected if The OIDC configuration uses implicit flow rather than authorization code flow with PKCE.
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Inspect JWT validation behaviorIf code inspection is possible, examine the JWT parsing implementation in the OpenOlat codebase, specifically the JSONWebToken.parse() method and getAccessToken() methods to confirm signature verification is not performed.Affected if The JWT parsing code does not perform cryptographic signature verification against the Identity Provider's JWKS endpoint.
You are affected if OpenOlat version is between 10.5.4 and 20.2.4 inclusive AND OpenID Connect implicit flow authentication is enabled.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped20.2.5
Upgrade OpenOlat to version 20.2.5 or later which implements proper JWT signature verification in the OpenID Connect flow.
20.2.5
- Identify the current OpenOlat version running in your environment
- Plan a maintenance window for the upgrade
- Back up the existing OpenOlat database and configuration files
- Upgrade OpenOlat to version 20.2.5 or later
- Verify the upgrade was successful by checking the version number
- Test the OpenID Connect authentication flow to confirm JWT signature verification is now working
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation2.0 h
- Testing3.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-31946 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-31946 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data