CVE-2026-33439
Pre-Authentication Remote Code Execution via `jato.clientSession` Deserialization in OpenAM
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. 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.
- Affected
- OpenIdentityPlatform · OpenAM
- CVSS v4.0 GITHUB
- 9.3 CRITICAL
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS v4.0 GitHub
- 9.3 CRITICAL
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 - CVSS v3.1 NVD
- 9.8 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - EPSS
- 8.43% chance of exploitation in the next 30 days, 95th percentile
- Nuclei
- critical · CWE-502
- Published
- 2026-04-07
- Updated
- 2026-04-08
Proof-of-concept exploits (6)
- TheMalwareGuardian/CVE-2026-3343911★ · 2026-05-01
- Ibonok/CVE-2026-33439-PoC2★ · 2026-04-28
- infernosalex/CVE-2026-33439-Python-PoC4★ · 2026-09-12
- JonasChen0103/CVE-2026-33439-PoC0★ · 2026-09-19
- rh33t/CVE-2026-33439-Poc0★ · 2026-09-29
- amis13/openam-clean0★ · 2026-10-07