NCSC-2026-0130

Vulnerability from csaf_ncscnl - Published: 2026-04-30 08:00 - Updated: 2026-04-30 08:00
Summary
Kwetsbaarheid verholpen in cPanel en WHM
Notes
The Netherlands Cyber Security Center (henceforth: NCSC-NL) maintains this page to enhance access to its information and security advisories. The use of this security advisory is subject to the following terms and conditions: NCSC-NL makes every reasonable effort to ensure that the content of this page is kept up to date, and that it is accurate and complete. Nevertheless, NCSC-NL cannot entirely rule out the possibility of errors, and therefore cannot give any warranty in respect of its completeness, accuracy or continuous keeping up-to-date. The information contained in this security advisory is intended solely for the purpose of providing general information to professional users. No rights can be derived from the information provided therein. NCSC-NL and the Kingdom of the Netherlands assume no legal liability or responsibility for any damage resulting from either the use or inability of use of this security advisory. This includes damage resulting from the inaccuracy of incompleteness of the information contained in the advisory. This security advisory is subject to Dutch law. All disputes related to or arising from the use of this advisory will be submitted to the competent court in The Hague. This choice of means also applies to the court in summary proceedings.
Feiten: cPanel heeft een kwetsbaarheid verholpen in cPanel en WHM producten, inclusief versies na 11.40 en vóór de specifieke gepatchte releases.
Interpretaties: De kwetsbaarheid betreft een authenticatieomzeiling die ontstaat door CRLF-injectie in sessiebestanden, waardoor aanvallers sessies kunnen vervalsen. Daarnaast is de loginflow zelf kwetsbaar, waardoor niet-geauthenticeerde externe aanvallers de authenticatiemechanismen kunnen omzeilen. Hierdoor kan ongeautoriseerde toegang tot het WHM control panel met rootrechten worden verkregen.
Oplossingen: cPanel heeft updates uitgebracht om de kwetsbaarheid te verhelpen. Zie bijgevoegde referenties voor meer informatie.
Kans: high
Schade: high
CWE-306: Missing Authentication for Critical Function
CVE-2026-41940

cPanel and WHM versions prior to specified releases, including those after 11.40, contain an authentication bypass vulnerability via CRLF injection in session files and login flow, allowing unauthenticated attackers to gain root-level control panel access.

9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE-306 - Missing Authentication for Critical Function
Affected products
Product Identifier Version Remediation
vers:unknown/*
cPanel / WHM
 vers:unknown/*
vers:unknown/*
cPanel / WP Squared
 vers:unknown/*
vers:unknown/*
cPanel / cPanel
 vers:unknown/*
vers:unknown/*
cPanel / cPanel/WHM
 vers:unknown/*
References
To clipboard 

{
  "document": {
    "category": "csaf_security_advisory",
    "csaf_version": "2.0",
    "distribution": {
      "tlp": {
        "label": "WHITE"
      }
    },
    "lang": "nl",
    "notes": [
      {
        "category": "legal_disclaimer",
        "text": "The Netherlands Cyber Security Center (henceforth: NCSC-NL) maintains this page to enhance access to its information and security advisories. The use of this security advisory is subject to the following terms and conditions:\n\n    NCSC-NL makes every reasonable effort to ensure that the content of this page is kept up to date, and that it is accurate and complete. Nevertheless, NCSC-NL cannot entirely rule out the possibility of errors, and therefore cannot give any warranty in respect of its completeness, accuracy or continuous keeping up-to-date. The information contained in this security advisory is intended solely for the purpose of providing general information to professional users. No rights can be derived from the information provided therein.\n\n    NCSC-NL and the Kingdom of the Netherlands assume no legal liability or responsibility for any damage resulting from either the use or inability of use of this security advisory. This includes damage resulting from the inaccuracy of incompleteness of the information contained in the advisory.\n    This security advisory is subject to Dutch law. All disputes related to or arising from the use of this advisory will be submitted to the competent court in The Hague. This choice of means also applies to the court in summary proceedings."
      },
      {
        "category": "description",
        "text": "cPanel heeft een kwetsbaarheid verholpen in cPanel en WHM producten, inclusief versies na 11.40 en v\u00f3\u00f3r de specifieke gepatchte releases.",
        "title": "Feiten"
      },
      {
        "category": "description",
        "text": "De kwetsbaarheid betreft een authenticatieomzeiling die ontstaat door CRLF-injectie in sessiebestanden, waardoor aanvallers sessies kunnen vervalsen. Daarnaast is de loginflow zelf kwetsbaar, waardoor niet-geauthenticeerde externe aanvallers de authenticatiemechanismen kunnen omzeilen. Hierdoor kan ongeautoriseerde toegang tot het WHM control panel met rootrechten worden verkregen.",
        "title": "Interpretaties"
      },
      {
        "category": "description",
        "text": "cPanel heeft updates uitgebracht om de kwetsbaarheid te verhelpen. Zie bijgevoegde referenties voor meer informatie.",
        "title": "Oplossingen"
      },
      {
        "category": "general",
        "text": "high",
        "title": "Kans"
      },
      {
        "category": "general",
        "text": "high",
        "title": "Schade"
      },
      {
        "category": "general",
        "text": "Missing Authentication for Critical Function",
        "title": "CWE-306"
      }
    ],
    "publisher": {
      "category": "coordinator",
      "contact_details": "cert@ncsc.nl",
      "name": "Nationaal Cyber Security Centrum",
      "namespace": "https://www.ncsc.nl/"
    },
    "references": [
      {
        "category": "external",
        "summary": "Reference",
        "url": "https://support.cpanel.net/hc/en-us/articles/40073787579671-cPanel-WHM-Security-Update-04-28-2026"
      }
    ],
    "title": "Kwetsbaarheid verholpen in cPanel en WHM",
    "tracking": {
      "current_release_date": "2026-04-30T08:00:11.291177Z",
      "generator": {
        "date": "2025-08-04T16:30:00Z",
        "engine": {
          "name": "V.A.",
          "version": "1.3"
        }
      },
      "id": "NCSC-2026-0130",
      "initial_release_date": "2026-04-30T08:00:11.291177Z",
      "revision_history": [
        {
          "date": "2026-04-30T08:00:11.291177Z",
          "number": "1.0.0",
          "summary": "Initiele versie"
        }
      ],
      "status": "final",
      "version": "1.0.0"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "vers:unknown/*",
                "product": {
                  "name": "vers:unknown/*",
                  "product_id": "CSAFPID-1"
                }
              }
            ],
            "category": "product_name",
            "name": "WHM"
          },
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "vers:unknown/*",
                "product": {
                  "name": "vers:unknown/*",
                  "product_id": "CSAFPID-2"
                }
              }
            ],
            "category": "product_name",
            "name": "WP Squared"
          },
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "vers:unknown/*",
                "product": {
                  "name": "vers:unknown/*",
                  "product_id": "CSAFPID-3"
                }
              }
            ],
            "category": "product_name",
            "name": "cPanel"
          },
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "vers:unknown/*",
                "product": {
                  "name": "vers:unknown/*",
                  "product_id": "CSAFPID-4"
                }
              }
            ],
            "category": "product_name",
            "name": "cPanel/WHM"
          }
        ],
        "category": "vendor",
        "name": "cPanel"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-41940",
      "cwe": {
        "id": "CWE-306",
        "name": "Missing Authentication for Critical Function"
      },
      "notes": [
        {
          "category": "other",
          "text": "Missing Authentication for Critical Function",
          "title": "CWE-306"
        },
        {
          "category": "description",
          "text": "cPanel and WHM versions prior to specified releases, including those after 11.40, contain an authentication bypass vulnerability via CRLF injection in session files and login flow, allowing unauthenticated attackers to gain root-level control panel access.",
          "title": "Summary"
        },
        {
          "category": "general",
          "text": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
          "title": "CVSSV4"
        }
      ],
      "product_status": {
        "known_affected": [
          "CSAFPID-1",
          "CSAFPID-2",
          "CSAFPID-3",
          "CSAFPID-4"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2026-41940 | NCSC-NL Website",
          "url": "https://vulnerabilities.ncsc.nl/csaf/v2/2026/cve-2026-41940.json"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "baseScore": 9.8,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "products": [
            "CSAFPID-1",
            "CSAFPID-2",
            "CSAFPID-3",
            "CSAFPID-4"
          ]
        }
      ],
      "title": "CVE-2026-41940"
    }
  ]
}



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