{"id":"CVE-2026-87944","kind":"vulnerability","aliases":["CVE-2026-87944"],"related":[],"title":"Drupal SAML SSO Service Provider: improper certificate validation enables man-in-the-middle","description":"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.","summary":"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.","severity":"medium","cvss":4.8,"epss":0.00113,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["drupal","package","saml","self-hosted","sso"],"not_affected_if":["no-saml-sso-module","no-untrusted-network-path"],"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.\n- 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.","status":"open","published_at":"2026-10-22T02:17:03+00:00","first_seen_at":"2026-10-23T21:57:30+00:00","triaged_at":"2026-10-25T04:33:09+00:00","updated_at":"2026-10-25T04:33:09+00:00","category":"package","confidence":0.6,"triage":{"at":"2026-10-25T04:33:09Z","model":"claude-haiku-5-5","output":{"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.","reach":"network","title":"Drupal SAML SSO Service Provider: improper certificate validation enables man-in-the-middle","impact":"medium","summary":"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.","category":"package","nicknames":[],"who_cares":["drupal","saml","sso","self-hosted"],"confidence":0.6,"needs_auth":"no","worst_case":"attacker intercepts SSO logins and may impersonate users","analyst_note":"Confirm the fixed version and whether the flaw is in the SAML response or metadata validation, via https://nvd.nist.gov/vuln/detail/CVE-2026-87944 and the Drupal security advisory.","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.\n- Confirm whether the installed version is `3.2.0` or earlier.","needs_analyst":true,"not_affected_if":["no-saml-sso-module","no-untrusted-network-path"],"who_is_affected":"Drupal sites that use the SAML SSO - Service Provider module to sign users in through an external identity provider are exposed. Sites that do not use this module for SSO, or that run it only on a trusted private network with no untrusted path between the site and the identity provider, are at lower risk.","user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"medium"},"cost_usd":0.000649,"input_tokens":3351,"output_tokens":627,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-2026':16A,19A '-87944':17A,20A '0.0.0':60B,92C '3.2.0':62B,94C 'adversari':78C 'affect':66B,85C 'aitm':82C 'allow':77C 'alter':55B 'attack':43B 'certif':7A,39B,68C 'cve':15A,18A 'drupal':1A,21B,29B,72C 'enabl':9A 'host':26B 'ident':50B 'improp':6A,67C 'intercept':53B 'issu':84C 'list':64B 'man':11A 'man-in-the-middl':10A 'middl':14A,81C 'modul':34B 'network':42B 'packag':22B 'posit':44B 'proper':37B 'provid':5A,33B,51B,76C,89C 'saml':2A,23B,30B,73C,86C 'self':25B 'self-host':24B 'servic':4A,32B,75C,88C 'site':47B 'sso':3A,27B,31B,56B,74C,87C 'traffic':57B 'valid':8A,38B,69C 'version':58B,90C 'vulner':70C","nicknames":[],"mitigations":[],"who_affected":"Drupal sites that use the SAML SSO - Service Provider module to sign users in through an external identity provider are exposed. Sites that do not use this module for SSO, or that run it only on a trusted private network with no untrusted path between the site and the identity provider, are at lower risk.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-22T02:17:03+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N","cvss_by":"134c704f-9b21-4f2e-91b3-4a467353bcc0","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-87944","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-87944","severity":null,"published_at":"2026-10-22T02:17:03+00:00","modified_at":"2026-10-22T17:17:00+00:00","first_seen_at":"2026-10-23T21:57:30+00:00","fetched_at":"2026-10-23T22:29:02+00:00","note":null},{"source":"epss","external_id":"CVE-2026-87944","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-87944","severity":null,"published_at":null,"modified_at":null,"first_seen_at":"2026-10-24T07:15:52+00:00","fetched_at":"2026-10-24T07:15:52+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}