---
id: "CVE-2026-87944"
kind: "vulnerability"
aliases: ["CVE-2026-87944"]
title: "Drupal SAML SSO Service Provider: improper certificate validation enables man-in-the-middle"
severity: "medium"
cvss: 4.8
epss: 0.00113
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["drupal", "package", "saml", "self-hosted", "sso"]
not_affected_if: ["no-saml-sso-module", "no-untrusted-network-path"]
published_at: "2026-10-22T02:17:03+00:00"
first_seen_at: "2026-10-23T21:57:30+00:00"
updated_at: "2026-10-25T04:33:09+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-87944", "first_seen_at": "2026-10-23T21:57:30+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-87944", "first_seen_at": "2026-10-24T07:15:52+00:00"}]
---

# Drupal SAML SSO Service Provider: improper certificate validation enables man-in-the-middle

The Drupal SAML SSO - Service Provider module does not properly validate certificates, so a network attacker positioned between the site and its identity provider can intercept or alter SSO traffic. Versions from 0.0.0 through 3.2.0 are listed as affected.

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

## How to check

- Check the installed version of the module with `drush pm:list --filter=saml` or by reviewing the module's `composer.lock` entry for the SAML SSO - Service Provider package.
- Confirm whether the installed version is `3.2.0` or earlier.

## Fix

- Upgrade the Drupal SAML SSO - Service Provider module to a version later than `3.2.0`; the fixed version is unknown from the sources.

## Timeline

- 2026-10-23T21:57:30+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-87944
- 2026-10-24T07:15:52+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-87944

## From the sources

Improper Certificate Validation vulnerability in Drupal SAML SSO - Service Provider  allows Adversary in the Middle (AiTM). This issue affects SAML SSO - Service Provider  versions: from 0.0.0 to 3.2.0.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_