---
id: "CVE-2026-123540"
page: "https://infrastack.ai/live/CVE-2026-123540"
kind: "vulnerability"
aliases: ["CVE-2026-123540"]
title: "OpenAM: incomplete output encoding lets SAML 1.x identity provider alter attributes"
severity: "low"
cvss: 2.0
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["identity", "openam", "package", "saml"]
not_affected_if: ["no-saml-1x-idp", "openam-16.1.4-or-later"]
published_at: "2026-11-08T02:16:44+00:00"
first_seen_at: "2026-11-08T02:21:10+00:00"
updated_at: "2026-11-08T02:26:48+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-123540", "first_seen_at": "2026-11-08T02:21:10+00:00"}]
exploit_sources: []
---

# OpenAM: incomplete output encoding lets SAML 1.x identity provider alter attributes

Link for people: https://infrastack.ai/live/CVE-2026-123540 (this .md is for agents)

OpenAM before 16.1.4 does not fully encode output in the service provider auto-submitted form, so a SAML 1.x identity provider can inject content. An attacker who controls a trusted identity provider can change attribute names or values before they reach the application.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the OpenAM version in use; it is affected if it is below `16.1.4`.
- Check whether any service provider trusts SAML 1.x identity providers that an outside party could control.

## Fix

- OpenAM: move to `16.1.4` or later (per the advisory data in the sources).

## Timeline

- 2026-11-08T02:21:10+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-123540

## Documents

- [advisory] Vendor advisory: github.com https://github.com/OpenIdentityPlatform/OpenAM/security/advisories/GHSA-pw99-8h4m-p3gm
- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/openam-before-16.1.4-incomplete-attribute-encoding-in-saml-1-x-form-post

## From the sources

OpenAM before 16.1.4 contains an incomplete output encoding vulnerability that allows a SAML 1.x identity provider to alter attribute values by injecting unencoded content into the service provider auto-submitted form. Attackers controlling a trusted identity provider can craft assertion attribute names or values that reach the target application in modified form, undermining the integrity of received attributes.

---

_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_