Vulnerability-Lookup

(CVE-2026-16639)

Vulnerability from drupal – Published: 2026-07-22 17:53 – Updated: 2026-07-22 17:53 – Source website

Details

In a scenario of a multilingual website with different domain names per language, this module enables you to be automatically connected across the language domains if you are logged on the main language domain.

The module doesn't sufficiently validate a short-lived token, allowing an attacker to bypass access control and authenticate as a victim user.

This vulnerability is mitigated by the fact that an attacker must appear to originate from the same client IP as the victim.

Credits

Drew Webber (mcdruid) www.drupal.org/u/mcdruid

References

URL

Type

https://www.drupal.org/sa-contrib-2026-081

WEB

JSON

To clipboard

{
  "affected": [
    {
      "database_specific": {
        "affected_versions": "\u003c1.8.0"
      },
      "package": {
        "ecosystem": "Packagist:https://packages.drupal.org/8",
        "name": "drupal/i18n_sso"
      },
      "ranges": [
        {
          "database_specific": {
            "constraint": "\u003c1.8.0"
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.8.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "severity": []
    }
  ],
  "aliases": [
    "CVE-2026-16639"
  ],
  "credits": [
    {
      "contact": [
        "https://www.drupal.org/u/mcdruid"
      ],
      "name": "Drew Webber (mcdruid)"
    }
  ],
  "details": "In a scenario of a multilingual website with different domain names per language, this module enables you to be automatically connected across the language domains if you are logged on the main language domain.\n\nThe module doesn\u0027t sufficiently validate a short-lived token, allowing an attacker to bypass access control and authenticate as a victim user.\n\nThis vulnerability is mitigated by the fact that an attacker must appear to originate from the same client IP as the victim.",
  "id": "DRUPAL-CONTRIB-2026-081",
  "modified": "2026-07-22T17:53:35.000Z",
  "published": "2026-07-22T17:53:35.000Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://www.drupal.org/sa-contrib-2026-081"
    }
  ],
  "schema_version": "1.7.0"
}

CVE-2026-16639 (GCVE-0-2026-16639)

Vulnerability from cvelistv5 – Published: 2026-08-25 22:22 – Updated: 2026-08-26 15:23

Title

Internationalization Single Sign-On - Critical - Access bypass - SA-CONTRIB-2026-081

Summary

Authentication Bypass Using an Alternate Path or Channel vulnerability in Drupal Internationalization Single Sign-On allows Authentication Bypass. This issue affects Internationalization Single Sign-On versions: from 0.0.0 to 1.8.0.

Severity

9.8 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

SSVC

Exploitation: none Automatable: yes Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-26 15:22 UTC

CWE

CWE-288 - Authentication Bypass Using an Alternate Path or Channel

Assigner

drupal mitre root

References

1 reference

URL	Tags
https://www.drupal.org/sa-contrib-2026-081

Impacted products

1 product

Vendor	Product	Version
Drupal	Internationalization Single Sign-On	Affected: 0.0.0 , < 1.8.0 (semver)

Date Public

2026-07-22 17:53

Credits

Drew Webber (mcdruid) Florent Torregrosa (grimreaper) Drew Webber (mcdruid) Bram Driesen (bramdriesen) Greg Knaddison (greggles) Drew Webber (mcdruid) Juraj Nemec (poker10)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "HIGH",
              "baseScore": 9.8,
              "baseSeverity": "CRITICAL",
              "confidentialityImpact": "HIGH",
              "integrityImpact": "HIGH",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-16639",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-26T15:22:48.162413Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-26T15:23:15.811Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://www.drupal.org/project/i18n_sso",
          "product": "Internationalization Single Sign-On",
          "repo": "https://git.drupalcode.org/project/i18n_sso",
          "vendor": "Drupal",
          "versions": [
            {
              "lessThan": "1.8.0",
              "status": "affected",
              "version": "0.0.0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Drew Webber (mcdruid)"
        },
        {
          "lang": "en",
          "type": "remediation developer",
          "value": "Florent Torregrosa (grimreaper)"
        },
        {
          "lang": "en",
          "type": "remediation developer",
          "value": "Drew Webber (mcdruid)"
        },
        {
          "lang": "en",
          "type": "coordinator",
          "value": "Bram Driesen (bramdriesen)"
        },
        {
          "lang": "en",
          "type": "coordinator",
          "value": "Greg Knaddison (greggles)"
        },
        {
          "lang": "en",
          "type": "coordinator",
          "value": "Drew Webber (mcdruid)"
        },
        {
          "lang": "en",
          "type": "coordinator",
          "value": "Juraj Nemec (poker10)"
        }
      ],
      "datePublic": "2026-07-22T17:53:35.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "Authentication Bypass Using an Alternate Path or Channel vulnerability in Drupal Internationalization Single Sign-On allows Authentication Bypass. This issue affects Internationalization Single Sign-On versions: from 0.0.0 to 1.8.0."
        }
      ],
      "impacts": [
        {
          "capecId": "CAPEC-115",
          "descriptions": [
            {
              "lang": "en",
              "value": "CAPEC-115 Authentication Bypass"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-288",
              "description": "CWE-288 Authentication Bypass Using an Alternate Path or Channel",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-25T22:22:12.799Z",
        "orgId": "2c85b837-eb8b-40ed-9d74-228c62987387",
        "shortName": "drupal"
      },
      "references": [
        {
          "url": "https://www.drupal.org/sa-contrib-2026-081"
        }
      ],
      "title": "Internationalization Single Sign-On - Critical - Access bypass - SA-CONTRIB-2026-081"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "2c85b837-eb8b-40ed-9d74-228c62987387",
    "assignerShortName": "drupal",
    "cveId": "CVE-2026-16639",
    "datePublished": "2026-08-25T22:22:12.799Z",
    "dateReserved": "2026-07-22T17:06:41.738Z",
    "dateUpdated": "2026-08-26T15:23:15.811Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.