CVE-2026-33439Public exploitNetwork attack vector

Pre-authentication command execution via client-session deserialization

Published Apr 7, 2026 · Updated Apr 7, 2026

Unsafe Java deserialization in OpenAM before 16.0.6 allows remote attackers to execute arbitrary commands through jato.clientSession. ClientSession.deserializeAttributes passes the HTTP parameter through Encoder.deserialize to ApplicationObjectInputStream.readObject without a class allowlist. Any unauthenticated request to a JATO ViewBean endpoint whose JSP renders a jato:form tag can run commands as the application-server user.

CVSS severity9.3
Critical
EPSS probability10.01%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Unsafe Java deserialization in OpenAM before 16.0.6 allows remote attackers to execute arbitrary commands through jato.clientSession. ClientSession.deserializeAttributes passes the HTTP parameter through Encoder.deserialize to ApplicationObjectInputStream.readObject without a class allowlist. Any unauthenticated request to a JATO ViewBean endpoint whose JSP renders a jato:form tag can run commands as the application-server user.

The record

CVE
CVE-2026-33439
Published
Apr 7, 2026
Updated
Apr 7, 2026
Vendor
Open Identity Platform
Product
OpenAM
Classifications
CWE-502, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 7, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 7, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 16.0.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Open Identity Platform · OpenAMversion=< 16.0.6

Published CVSS scores

9.3GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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 exploitPublished

Weakness, pattern, technique

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

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo