CVE-2026-33439
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedOpen Access Management (OpenAM) is an access management solution. Prior to 16.0.6, OpenIdentityPlatform OpenAM is vulnerable to pre-authentication Remote Code Execution (RCE) via unsafe Java deserialization of the jato.clientSession HTTP parameter. This bypasses the WhitelistObjectInputStream mitigation that was applied to the jato.pageSession parameter after CVE-2021-35464. An unauthenticated attacker can achieve arbitrary command execution on the server by sending a crafted serialized Java object as the jato.clientSession GET/POST parameter to any JATO ViewBean endpoint whose JSP contains <jato:form> tags (e.g., the Password Reset pages). This vulnerability is fixed in 16.0.6.
In the news
Third-party coverageSurfaced from public web coverage — external links open in a new tab.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceOpenIdentityPlatform OpenAM versions prior to 16.0.6 contain a pre-authentication Remote Code Execution vulnerability. The jato.clientSession HTTP parameter accepts serialized Java objects without proper sanitization, allowing unauthenticated attackers to execute arbitrary commands by sending crafted malicious objects to JATO ViewBean endpoints containing <jato:form> tags (such as Password Reset pages). This flaw bypasses a previous mitigation (WhitelistObjectInputStream) that was applied to the similar jato.pageSession parameter after CVE-2021-35464.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 16.0.6CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify OpenAM versionAccess the OpenAM admin console or check the version file in the OpenAM installation directory. Common paths include /opt/openam or the version displayed on the login page. Compare the installed version to the affected range: versions prior to 16.0.6 are vulnerable.Affected if The installed OpenAM version is below 16.0.6
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Confirm JATO endpoint exposureIdentify if JATO ViewBean endpoints with <jato:form> tags are accessible. These typically include password reset, forgotten username, and other self-service pages. Check the deployed web.xml or application configuration for JATO-related servlet mappings.Affected if JATO ViewBean endpoints (such as Password Reset) are publicly accessible without authentication
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Verify jato.clientSession parameter acceptanceInspect HTTP traffic or application logs to determine if the jato.clientSession parameter is being accepted in HTTP requests. This parameter is processed by JATO ViewBean components and uses Java deserialization.Affected if The jato.clientSession parameter is accepted and processed by the application without validation
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Check for WhitelistObjectInputStream on jato.pageSessionReview the OpenAM source code or decompile the relevant JAR files to examine the ObjectInputStream implementation used for jato.clientSession versus jato.pageSession. CVE-2021-35464 added whitelist protection to jato.pageSession but this CVE specifically bypasses that protection by targeting jato.clientSession.Affected if The jato.clientSession parameter uses an unprotected ObjectInputStream without whitelist validation, while jato.pageSession has the CVE-2021-35464 mitigation applied
You are affected if your OpenAM version is below 16.0.6 AND the jato.clientSession parameter is being processed by accessible JATO ViewBean endpoints without proper deserialization controls.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped16.0.6
Upgrade to OpenAM version 16.0.6 or later. As an interim measure, consider blocking or rate-limiting access to the Password Reset endpoints at the network level until the upgrade can be completed.
16.0.6
- Identify current OpenAM version by checking the deployment or admin console
- Download OpenAM version 16.0.6 from the official OpenIdentityPlatform repository or your distribution channel
- Review the upgrade guide for 16.0.6 to understand prerequisites and migration requirements
- Create a complete backup of the current OpenAM installation including configuration, databases, and deployment artifacts
- Test the upgrade in a non-production environment to verify functionality
- Deploy version 16.0.6 to production following standard deployment procedures
- Verify the installation and test that authentication flows (including password reset) work correctly
- Confirm the jato.clientSession parameter is now properly handled with safe deserialization
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation6.0 h
- Implementation10.0 h
- Testing8.0 h
- Review / QA3.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-33439 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-33439 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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