How severe is CVE-2026-44203?

No CVSS score has been assigned to CVE-2026-44203 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-44203?

CVE-2026-44203 affects the following packages: org.openidentityplatform.openam:openam-oauth2 (Maven). Ecosystems affected: Maven.

How do I fix CVE-2026-44203?

Update org.openidentityplatform.openam:openam-oauth2 to 16.1.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-44203 is resolved across your whole dependency graph.

How do I detect CVE-2026-44203 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.openidentityplatform.openam:openam-oauth2, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-44203 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-2026-44203 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-44203 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-2026-44203?

CVE-2026-44203 has an EPSS (Exploit Prediction Scoring System) score of 0.6%, placing it in the 48th 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-2026-44203?

CVE-2026-44203 is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2026-44203 published, and has it been updated?

CVE-2026-44203 was published on September 15, 2026 and was last updated on October 28, 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-2026-44203 — openam-oauth2

Fix: OpenIdentityPlatform/OpenAM@078bd47

CVE-2026-44203 is a Cross-site Scripting (XSS) vulnerability in org.openidentityplatform.openam:openam-oauth2. A fix is available for org.openidentityplatform.openam:openam-oauth2 — see the affected versions and patch details below.

OpenAM: Pre-auth Reflected XSS in OAuth2 / OIDC response_mode=form_post via state parameter (FormPostResponse.ftl)

Also known asGHSA-fq9h-c788-fx73

Published

Sep 15, 2026

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 4, 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-2026-44203.

EPSS Exploitation Probability

via FIRST.org ↗

0.6%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs48th percentile — riskier than 48% 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-oauth2

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

Open Access Management (OpenAM) is an access management solution. Prior to 16.1.1, the OAuth 2.0 and OpenID Connect authorization endpoint does not sufficiently encode user-supplied parameters before FormPostResponse.ftl and checkSession.ftl render them into HTML for the form_post response mode. An unauthenticated attacker can induce a user to open a crafted authorization request and execute script in the OpenAM origin. This issue is fixed in version 16.1.1.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.openidentityplatform.openam:openam-oauth2`	≥ 13.0.0&&< 16.1.1	16.1.1`org.openidentityplatform.openam:openam-oauth2:16.1.1`

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-oauth2, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.openidentityplatform.openam:openam-oauth2 to 16.1.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-44203 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

O3 Security · Impact-Aware SCA

Is CVE-2026-44203 in your dependencies?

Find it across Maven, including transitive dependencies.

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