vulnerability / NVI-00003647 / Revision 1
Webauthn has a User Verification Downgrade via Default-Open ClientOverridePolicy
OSV carries this publisher advisory for web-auth/webauthn-framework. This is an aggregated source copy; consult the original publisher and compare update dates.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
web-auth/webauthn-framework
source listedECOSYSTEM: introduced 5.3.0; fixed 5.3.1
## Summary In version 5.3.0 of the Symfony bundle, `Webauthn\Bundle\Policy\ClientOverridePolicy` defaulted to allowing all client overrides, including `userVerification`. A client could send `{"userVerification": "discouraged"}` in the assertion or attestation options request to override a server-configured `userVerification: required`, causing the emitted WebAuthn options to instruct the authenticator to skip user verification. The `CheckUserVerification` ceremony step then read the same downgraded options and skipped its check. ## Affected versions - **Vulnerable**: 5.3.0 - **Patched**: 5.3.1 5.3.0 was released on 2026-05-01 and 5.3.1 was published roughly 18 hours later, on 2026-05-02. Practical exposure window was minimal. ## Note on earlier 5.x versions Versions 5.0.0 to 5.2.x did not ship `ClientOverridePolicy` (introduced in 5.3.0), so the exact code path described above does not apply. However, on those versions the `ProfileBasedRequestOptionsBuilder` and `ProfileBasedCreationOptionsBuilder` already passed the client-supplied `userVerification` value directly to the options factory, where the profile value is only applied via `??=`. The functional outcome (a client ca
03 / Response
What to do next
- vendor patch
The original advisory lists fixed boundaries 5.3.1 for web-auth/webauthn-framework. Confirm the publisher’s latest guidance.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database via OSV
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
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- GHSA-h4fw-6r7f-w494 ↗
GitHub Advisory Database via OSV · vendor advisory
Observed . GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.