How severe is CVE-2026-53660?

No CVSS score has been assigned to CVE-2026-53660 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-53660?

CVE-2026-53660 affects the following packages: org.openidentityplatform.openam:openam-core (Maven). Ecosystems affected: Maven.

How do I fix CVE-2026-53660?

Update org.openidentityplatform.openam:openam-core to 16.1.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-53660 is resolved across your whole dependency graph.

How do I detect CVE-2026-53660 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.openidentityplatform.openam:openam-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-53660 if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is CVE-2026-53660 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-53660 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-53660?

CVE-2026-53660 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 33th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-53660?

CVE-2026-53660 is classified as CWE-1004 (CWE-1004), CWE-1188 (CWE-1188), CWE-1275 (CWE-1275). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-53660 published, and has it been updated?

CVE-2026-53660 was published on September 15, 2026 and was last updated on September 25, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕ Maven

Not in CISA KEV

CVE-2026-53660 — openam-core

Fix: OpenIdentityPlatform/OpenAM@2af5972

CVE-2026-53660 is a CWE-1004 vulnerability in org.openidentityplatform.openam:openam-core. A fix is available for org.openidentityplatform.openam:openam-core — see the affected versions and patch details below.

OpenAM Insecure SSO Cookie Initialization

Also known asGHSA-fpmh-vx4h-xc33

Published

Sep 15, 2026

Updated

Sep 25, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 2, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

A successful exploit gives an attacker total control of the affected component, not partial access.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-53660.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs33th percentile — riskier than 33% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

☕org.openidentityplatform.openam:openam-core

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

Summary

Description An Insecure Default Initialization of Resource (CWE-1188) issue in the OpenAM default configuration ships the iPlanetDirectoryPro SSO cookie with HttpOnly=false. Also, the iPlanetDirectoryPro SSO cookie is used as a CSRF token in OAuth/OIDC flows. This affects OpenAM Community Edition through version 16.0.6 and was patched in version 16.1.1.

Impact

A single click on an attacker link may yield full SSO session theft of any authenticated console user when chained with any other same-origin XSS in the OpenAM origin. The missing SameSite default also widens the CSRF surface. Also, because the consent flow reuses the SSO cookie as its CSRF token, any XSS in the OpenAM origin both steals the session and completes attacker-driven OAuth consent grants in one step.

Patch

This has been patched in OpenAM Community Edition version 16.1.1. Users are encouraged to update to the latest release.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.openidentityplatform.openam:openam-core`	all versions	16.1.1`org.openidentityplatform.openam:openam-core:16.1.1`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.openidentityplatform.openam:openam-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.openidentityplatform.openam:openam-core to 16.1.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-53660 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Frequently Asked Questions

## Summary **Description** An Insecure Default Initialization of Resource (CWE-1188) issue in the OpenAM default configuration ships the `iPlanetDirectoryPro` SSO cookie with `HttpOnly=false`. Also, the `iPlanetDirectoryPro` SSO cookie is used as a CSRF token in OAuth/OIDC flows. This affects OpenAM Community Edition through version 16.0.6 and was patched in version 16.1.1. ## Impact A single click on an attacker link may yield full SSO session theft of any authenticated console user when chained with any other same-origin XSS in the OpenAM origin. The missing `SameSite` default also widens

O3 Security · Impact-Aware SCA

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