CVE-2026-62263Network attack vectorHinoki check available

Pre-authentication RCE via nested deserialization filter bypass

Published Sep 15, 2026 · Updated Sep 15, 2026

Deserialization in OpenAM before 16.1.2 allows remote attackers to execute code through a crafted WebAuthn userHandle. WebAuthnAuthentication.deserialize allows every serialized object below the AuthenticatorImpl root, so nested readObject or readResolve methods run before casting and assertion checks. Exploitation requires no authentication but does require a usable gadget class on the server classpath.

CVSS severity9.2
Critical
EPSS probability0.55%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Deserialization in OpenAM before 16.1.2 allows remote attackers to execute code through a crafted WebAuthn userHandle. WebAuthnAuthentication.deserialize allows every serialized object below the AuthenticatorImpl root, so nested readObject or readResolve methods run before casting and assertion checks. Exploitation requires no authentication but does require a usable gadget class on the server classpath.

The record

CVE
CVE-2026-62263
Published
Sep 15, 2026
Updated
Sep 15, 2026
Vendor
Open Identity Platform
Product
OpenAM
Classifications
CWE-502, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 15, 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=< 16.1.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Open Identity Platform · OpenAMversion=< 16.1.2

Published CVSS scores

9.2GitHubCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA: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 exploitUnconfirmed

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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