GHSA-GF8H-GQ53-288J
Vulnerability from github – Published: 2026-07-24 21:08 – Updated: 2026-07-24 21:08Summary
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.
{
"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"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.