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GHSA-GF8H-GQ53-288J

Vulnerability from github – Published: 2026-07-24 21:08 – Updated: 2026-07-24 21:08
VLAI
Summary
OpenAM: WebAuthn Java deserialization RCE via ObjectInputFilter depth>1 bypass
Details

Summary

The GHSA-6c99-87fr-6q7r fix wrapped WebAuthn authenticator deserialization in an ObjectInputFilter meant to allow only AuthenticatorImpl, but it short-circuits to ALLOWED for any object at stream depth > 1. Because the Java serialization filter is consulted for every class in the graph (and depth == 1 only for the root's concrete class), the allowlist constrains only the root and leaves the entire nested graph unchecked.

Impact

An attacker can craft a stream rooted at AuthenticatorImpl with an arbitrary gadget chain nested inside. The gadget's readObject/readResolve executes during readObject() — before the cast and before any assertion verification — enabling remote code execution when a gadget is on the classpath. The deserialization sink is reached pre-authentication via an attacker-chosen userHandle.

Severity
9.2 (Critical)
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
Show details on source website
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{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 16.1.1"
      },
      "package": {
        "ecosystem": "Maven",
        "name": "org.openidentityplatform.openam:openam-auth-webauthn"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "16.1.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-62263"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-502"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-24T21:08:46Z",
    "nvd_published_at": null,
    "severity": "CRITICAL"
  },
  "details": "### Summary\nThe GHSA-6c99-87fr-6q7r fix wrapped WebAuthn authenticator deserialization in an `ObjectInputFilter` meant to allow only `AuthenticatorImpl`, but it short-circuits to `ALLOWED` for any object at stream `depth \u003e 1`. Because the Java serialization filter is consulted for every class in the graph (and `depth == 1` only for the root\u0027s concrete class), the allowlist constrains only the root and leaves the entire nested graph unchecked.\n\n### Impact\nAn attacker can craft a stream rooted at `AuthenticatorImpl` with an arbitrary gadget chain nested inside. The gadget\u0027s `readObject`/`readResolve` executes during `readObject()` \u2014 before the cast and before any assertion verification \u2014 enabling remote code execution when a gadget is on the classpath. The deserialization sink is reached pre-authentication via an attacker-chosen `userHandle`.",
  "id": "GHSA-gf8h-gq53-288j",
  "modified": "2026-07-24T21:08:46Z",
  "published": "2026-07-24T21:08:46Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/OpenIdentityPlatform/OpenAM/security/advisories/GHSA-gf8h-gq53-288j"
    },
    {
      "type": "WEB",
      "url": "https://github.com/OpenIdentityPlatform/OpenAM/commit/9dd0fbe07f70f118cf45042d3a9ffb32f3c21e08"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/OpenIdentityPlatform/OpenAM"
    },
    {
      "type": "WEB",
      "url": "https://github.com/OpenIdentityPlatform/OpenAM/releases/tag/16.1.2"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "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",
      "type": "CVSS_V4"
    }
  ],
  "summary": "OpenAM: WebAuthn Java deserialization RCE via ObjectInputFilter depth\u003e1 bypass"
}



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