CVE-2026-30964Public exploitNetwork attack vector

Authentication response acceptance via host-only origin matching

Published Mar 10, 2026 · Updated Mar 10, 2026

Origin validation error in Webauthn Framework before 5.2.4 allows remote attackers to have same-host, cross-port WebAuthn responses accepted. CheckAllowedOrigins parses configured origins and clientDataJSON.origin to host values, then returns on host match before scheme, port, or HTTPS checks. Exploitation requires allowed_origins and user interaction; an accepted registration or authentication response bypasses the configured origin boundary.

CVSS severity5.4
Medium
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Origin validation error in Webauthn Framework before 5.2.4 allows remote attackers to have same-host, cross-port WebAuthn responses accepted. CheckAllowedOrigins parses configured origins and clientDataJSON.origin to host values, then returns on host match before scheme, port, or HTTPS checks. Exploitation requires allowed_origins and user interaction; an accepted registration or authentication response bypasses the configured origin boundary.

The record

CVE
CVE-2026-30964
Published
Mar 10, 2026
Updated
Mar 10, 2026
Vendor
Web-Authentication
Product
Webauthn Framework
Classifications
CWE-346, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 10, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 10, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 5.2.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Web-Authentication · Webauthn Frameworkversion=< 5.2.4
Web-Authentication · Webauthn Libversion=< 5.2.4
Web-Authentication · Webauthn Symfony Bundleversion=< 5.2.4

Published CVSS scores

5.4GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-346Origin Validation Error
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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