CVE-2026-33439 Details.
OpenAM <= 16.0.5 - Pre-Auth RCE via jato.clientSession Deserialization
Atlas does not check this one. Not a plain web check.
This weakness is not found through ordinary web pages. It needs a different kind of connection to the service. Atlas only runs plain web, DNS and TLS checks, so it does not run this one.
About CVE-2026-33439. What It Means.
Open 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. This vulnerability is fixed in 16.0.6.
Affected Product. What Is Hit.
- Vendor
- openidentityplatform
- Product
- Openidentityplatform OpenAM
FAQ
Common Questions.
OpenAM <= 16.0.5 - Pre-Auth RCE via jato.clientSession Deserialization. Open 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. This vulnerability is fixed in 16.0.6.
No. This weakness is not found through ordinary web pages. It needs a different kind of connection to the service. Atlas only runs plain web, DNS and TLS checks, so it does not run this one. The facts about CVE-2026-33439 are on this page, and you can request a demo to see how Brandefense watches your whole external attack surface.
CVE-2026-33439 is not on the CISA Known Exploited Vulnerabilities list at the time of writing, but it is still worth fixing.
Update Openidentityplatform OpenAM to the latest version from the vendor, or follow the vendor's advice to switch off the affected feature. Vendor links are listed on this page when they are known.
This page lists the public facts about CVE-2026-33439. Atlas does not run a check for it, so nothing here says whether a particular site is affected.