NVD / CVE Program· CNA GitHub_M

CVE-2026-33439: Pre-Authentication Remote Code Execution via `jato.clientSession` Deserialization in OpenAM

Noroxi assessment

Priority: Plan (action score 40/100)

A ready-made attack module is public (Nuclei); exploiting it takes no special expertise.
Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
Probability of exploitation in the next 30 days: 9.3% (FIRST EPSS); higher than 95.3% of all records.
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
According to CISA the attack is automatable: targets can be found by mass scanning.
Fixed version: OpenIdentityPlatform OpenAM 16.0.6.

Add it to your regular patch cycle. Upgrade to OpenIdentityPlatform OpenAM 16.0.6 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

CriticalCVSS 9.3 · v4.0—Proof of concept Fix available

GHSA-2cqq-rpvq-g5qj

Published: Apr 7, 2026
Updated: Jul 24, 2026
EPSS: 9.3% · 95th percentile
CWE: CWE-502

Report tools

JSON

Action score

Plan

Add it to your regular patch cycle.

CVSS: 37 / 40 · 9.3 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 3 / 30 · 9.3%

CISA SSVC decision

Exploitation: none
Automatable: yes
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · GitHub_M: 9.3; NVD has not scored this yet; the score shown is the CNA’s.

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

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
Proof of concept exists, no weaponized module
A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
openidentityplatform	openam	cpe:2.3:a:openidentityplatform:openam

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

openidentityplatform openambefore 16.0.6

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

OpenIdentityPlatform OpenAM
- < 16.0.6affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Maven	org.openidentityplatform.openam:openam	before 16.0.6	16.0.6

Same product

openidentityplatform: all records

Other highest-scoring records for the same primary product.

CVE-2026-62379OpenAM: Unauthenticated Remote Code Execution via Class.forName in AuthXMLUtils.createCustomCallback
39Monitor
CVE-2023-37471User impersonation using SAMLv1.x SSO in Open Access Management
39Monitor
CVE-2026-45052OpenAM Pre-auth User Profile Tampering via Anonymous SOAP Authn in Liberty IDPP/Discovery Endpoints
37Monitor

Published before and after this one in the same product

← EarlierCVE-2024-41667Jul 24, 2024 · OpenAM FreeMarker template injection
36Monitor
← EarlierCVE-2025-64099Nov 12, 2025 · OpenAM allows use of arbitrary OIDC requested claims values in id_token and user_info
32Monitor
Later →CVE-2026-41573Sep 15, 2026 · OpenAM LDAP Injection via `_queryId` Parameter
28Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
OpenIdentityPlatform OpenAM	16.0.6 · description	Vendor (CNA)
Maven:org.openidentityplatform.openam:openam	16.0.6	Package registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

Nuclei detection template ×1
Proof-of-concept repository on GitHub ×8

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
Source	Kind	Date
Nuclei detection template	Nuclei template CVE-2026-33439	—
Proof-of-concept repository on GitHub	stars:0	2026-04-27
Proof-of-concept repository on GitHub	stars:2	2026-04-28
Proof-of-concept repository on GitHub	stars:11	2026-04-30
Proof-of-concept repository on GitHub	stars:5	2026-09-12
Proof-of-concept repository on GitHub	stars:0	2026-09-19
Proof-of-concept repository on GitHub	stars:0	2026-09-20
Proof-of-concept repository on GitHub	stars:0	2026-10-07
Proof-of-concept repository on GitHub	stars:0	2026-10-29

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

PublishedApr 7, 2026
First PoCApr 27, 2026+19 d
TodayNov 2, 2026+209 d

EPSS, last 120 days+1% in 7 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

CVE-2026-45051161 days apartOpenAM Pre-auth RCE via Java Deserialization in WebAuthn Authenticator Storage
36Monitor
CVE-2026-62263161 days apartOpenAM: WebAuthn Java deserialization RCE via ObjectInputFilter depth>1 bypass
36Monitor
CVE-2026-45794161 days apartOpenAM Unsafe Java Deserialization via SNS
30Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: X

Weakness class (CWE)

CWE-502 · Deserialization of Untrusted Data

CVSS vector

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

nvd-secondary

Root cause

Data received over the network is deserialized into the language’s native object format without verifying its source. Code paths inside the object can be triggered during deserialization.

The bug in code

The whole CWE-502 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

python

1payload = sock.recv(65536)
2job = pickle.loads(payload)

Fixed

python

1payload = sock.recv(65536)
2if not hmac.compare_digest(sign(payload), header_sig):
3    raise PermissionError("invalid signature")
4job = JobSchema.validate(json.loads(payload))

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

Object InjectionCAPEC-586likelihood: Medium · High

ATT&CK techniques

—

Change log

Fix✗ → ✓Sep 28, 2026, 10:45 PM UTC

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All records

Noroxi analysis

What does it mean in your environment?

We use this product, ask for help

Data sources and verification

CNA: GitHub_M

CVE.org (CNA)Apr 8, 2026, 4:14 PM UTC
CISA ADPApr 8, 2026, 4:14 PM UTC
NVDJul 24, 2026, 7:10 PM UTC
FIRST EPSSNov 1, 2026, 12:00 AM UTC
OSV / GHSANov 2, 2026, 3:17 AM UTC
NucleiNov 2, 2026, 3:17 AM UTC
PoC-in-GitHubNov 2, 2026, 3:17 AM UTC

Each line is when that source was last processed for this record.