Summary
OpenAM: Pre-auth RCE via Java Deserialization in WebAuthn Authenticator Storage
Description
A deserialization of untrusted data vulnerability (CWE-502) exists in OpenAM's WebAuthn authentication module. Under certain conditions, this may allow an attacker to achieve arbitrary code execution in the context of the application server. This affects OpenAM Community Edition through version 16.0.6 and was patched in version 16.1.1.
This is not the default configuration. Exploitation requires that an attacker has previously been able to write attacker-controlled data to a storage attribute read by the WebAuthn module, and that the WebAuthn authentication flow is reachable.
Impact
WebAuthn is a modern shipped module, but the vulnerable configuration requires either the default storage attribute to become attacker-writable, or the WebAuthn userAttribute to be set to an attacker-writable string attribute. That is not the default, but it is feasible in deployments because the product exposes the storage attribute as a free-form admin setting and does not warn or enforce that it must be server-managed and non-user-writable. This may exist through delegated administration, provisioning, write access to the backing LDAP/directory user record, legacy REST self-registration, or unsafe reconfiguration of userAttribute.
In any deployment where the attribute becomes user writable, an attacker can execute arbitrary code as the application server user.
Untrusted serialized data is processed by a deserializer that can instantiate arbitrary objects or execute code as a side effect. Typical impact: arbitrary code execution or logic abuse.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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This has been patched in OpenAM Community Edition version 16.1.1. Users are encouraged to update to the latest release.
Frequently Asked Questions
- What is CVE-2026-45051? CVE-2026-45051 is a critical-severity insecure deserialization vulnerability in org.openidentityplatform.openam:openam-auth-webauthn (maven), affecting versions <= 16.0.6. It is fixed in 16.1.1. Untrusted serialized data is processed by a deserializer that can instantiate arbitrary objects or execute code as a side effect.
- Which versions of org.openidentityplatform.openam:openam-auth-webauthn are affected by CVE-2026-45051? org.openidentityplatform.openam:openam-auth-webauthn (maven) versions <= 16.0.6 is affected.
- Is there a fix for CVE-2026-45051? Yes. CVE-2026-45051 is fixed in 16.1.1. Upgrade to this version or later.
- Is CVE-2026-45051 exploitable, and should I be worried? Whether CVE-2026-45051 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-45051 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-45051? Upgrade
org.openidentityplatform.openam:openam-auth-webauthnto 16.1.1 or later.