CVE-2026-30964 is a medium-severity (CVSS 5.4) CWE-346 vulnerability in web-auth/webauthn-framework. A fix is available for web-auth/webauthn-framework — see the affected versions and patch details below.
Webauthn Framework: allowed_origins collapses URL-like origins to host-only values, bypassing exact origin validation
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-30964.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2026-30964 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,238 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
web-auth/webauthn-framework🐘web-auth/webauthn-lib🐘web-auth/webauthn-symfony-bundleReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
web-auth/webauthn-lib is an open source set of PHP libraries and a Symfony bundle to allow developers to integrate that authentication mechanism into their web applications. Prior to 5.2.4, when allowed_origins is configured, CheckAllowedOrigins reduces URL-like values to their host component and accepts on host match alone. This makes exact origin policies impossible to express: scheme and port differences are silently ignored. This vulnerability is fixed in 5.2.4.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | web-auth/webauthn-framework | ≥ 5.2.0&&< 5.2.4 | 5.2.4composer require web-auth/webauthn-framework:^5.2.4 |
| 🐘Packagist | web-auth/webauthn-lib | ≥ 5.2.0&&< 5.2.4 | 5.2.4composer require web-auth/webauthn-lib:^5.2.4 |
| 🐘Packagist | web-auth/webauthn-symfony-bundle | ≥ 5.2.0&&< 5.2.4 | 5.2.4composer require web-auth/webauthn-symfony-bundle:^5.2.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for web-auth/webauthn-framework, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update web-auth/webauthn-framework to 5.2.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-30964 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-30964 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-30964. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-30964 in your dependencies?
O3 Security finds CVE-2026-30964 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.