NCSC-2026-0095

Vulnerability from csaf_ncscnl - Published: 2026-03-12 14:45 - Updated: 2026-03-12 14:45
Summary
Kwetsbaarheid verholpen in pac4j-jwt

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
Pac4j heeft een kwetsbaarheid verholpen in de pac4j-jwt bibliotheek (specifiek voor versies voor 4.5.9, 5.7.9 en 6.3.3).
Interpretaties
De kwetsbaarheid bevindt zich in de JwtAuthenticator module van de pac4j-jwt bibliotheek. Deze kwetsbaarheid stelt een aanvaller die toegang heeft tot de RSA publieke sleutel van de server in staat om JWT-authenticatietokens te vervalsen. De fout omzeilt het proces van handtekeningverificatie, dat bedoeld is om de authenticiteit van tokens te valideren. Hierdoor kan een aanvaller zich voordoen als elke gebruiker, inclusief gebruikers met administratieve privileges. Alle applicaties die afhankelijk zijn van de kwetsbare pac4j-jwt versies voor JWT-authenticatie zijn getroffen.
Oplossingen
pac4j heeft updates uitgebracht om de kwetsbaarheid te verhelpen. Zie bijgevoegde referenties voor meer informatie.
Kans
medium
Schade
high
CWE-347
Improper Verification of Cryptographic Signature
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": "Pac4j heeft een kwetsbaarheid verholpen in de pac4j-jwt bibliotheek (specifiek voor versies voor 4.5.9, 5.7.9 en 6.3.3).",
        "title": "Feiten"
      },
      {
        "category": "description",
        "text": "De kwetsbaarheid bevindt zich in de JwtAuthenticator module van de pac4j-jwt bibliotheek. Deze kwetsbaarheid stelt een aanvaller die toegang heeft tot de RSA publieke sleutel van de server in staat om JWT-authenticatietokens te vervalsen. De fout omzeilt het proces van handtekeningverificatie, dat bedoeld is om de authenticiteit van tokens te valideren. Hierdoor kan een aanvaller zich voordoen als elke gebruiker, inclusief gebruikers met administratieve privileges. Alle applicaties die afhankelijk zijn van de kwetsbare pac4j-jwt versies voor JWT-authenticatie zijn getroffen.",
        "title": "Interpretaties"
      },
      {
        "category": "description",
        "text": "pac4j heeft updates uitgebracht om de kwetsbaarheid te verhelpen. Zie bijgevoegde referenties voor meer informatie.",
        "title": "Oplossingen"
      },
      {
        "category": "general",
        "text": "medium",
        "title": "Kans"
      },
      {
        "category": "general",
        "text": "high",
        "title": "Schade"
      },
      {
        "category": "general",
        "text": "Improper Verification of Cryptographic Signature",
        "title": "CWE-347"
      }
    ],
    "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://www.pac4j.org/blog/security-advisory-pac4j-jwt-jwtauthenticator.html"
      }
    ],
    "title": "Kwetsbaarheid verholpen in pac4j-jwt",
    "tracking": {
      "current_release_date": "2026-03-12T14:45:51.156512Z",
      "generator": {
        "date": "2025-08-04T16:30:00Z",
        "engine": {
          "name": "V.A.",
          "version": "1.3"
        }
      },
      "id": "NCSC-2026-0095",
      "initial_release_date": "2026-03-12T14:45:51.156512Z",
      "revision_history": [
        {
          "date": "2026-03-12T14:45:51.156512Z",
          "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": "pac4j-jwt"
          }
        ],
        "category": "vendor",
        "name": "pac4j"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-29000",
      "cwe": {
        "id": "CWE-347",
        "name": "Improper Verification of Cryptographic Signature"
      },
      "notes": [
        {
          "category": "other",
          "text": "Improper Verification of Cryptographic Signature",
          "title": "CWE-347"
        },
        {
          "category": "description",
          "text": "pac4j-jwt versions before 4.5.9, 5.7.9, and 6.3.3 contain a JwtAuthenticator vulnerability allowing attackers with the server\u0027s RSA public key to forge tokens and bypass signature verification, enabling user impersonation including administrators.",
          "title": "Summary"
        },
        {
          "category": "general",
          "text": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L",
          "title": "CVSSV4"
        }
      ],
      "product_status": {
        "known_affected": [
          "CSAFPID-1"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2026-29000 | NCSC-NL Website",
          "url": "https://vulnerabilities.ncsc.nl/csaf/v2/2026/cve-2026-29000.json"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "baseScore": 10.0,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L",
            "version": "3.1"
          },
          "products": [
            "CSAFPID-1"
          ]
        }
      ],
      "title": "CVE-2026-29000"
    }
  ]
}


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