Vulnerability-Lookup

PYSEC-2026-67

Vulnerability from pysec - Published: 2026-05-05 16:16 - Updated: 2026-05-20 09:19

Details

Jupyter Server is the backend for Jupyter web applications. In jupyter_server versions through 2.17.0, the next query parameter in the login flow is insufficiently validated in LoginFormHandler._redirect_safe(), which allows redirects to arbitrary external domains via values such as ///example.com. An attacker can use a crafted login URL to redirect users to a malicious site and facilitate phishing attacks. This issue is fixed in version 2.18.0.

Severity ?

6.1 (Medium)


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

Impacted products

Name	purl
jupyter-server	pkg:pypi/jupyter-server

Aliases

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "jupyter-server",
        "purl": "pkg:pypi/jupyter-server"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.18.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.0.0",
        "0.0.1",
        "0.0.2",
        "0.0.3",
        "0.0.4",
        "0.0.5",
        "0.1.0",
        "0.1.1",
        "0.2.0",
        "0.2.1",
        "0.3.0",
        "1.0.0",
        "1.0.0rc0",
        "1.0.0rc1",
        "1.0.0rc10",
        "1.0.0rc11",
        "1.0.0rc12",
        "1.0.0rc13",
        "1.0.0rc14",
        "1.0.0rc15",
        "1.0.0rc16",
        "1.0.0rc2",
        "1.0.0rc3",
        "1.0.0rc4",
        "1.0.0rc5",
        "1.0.0rc6",
        "1.0.0rc7",
        "1.0.0rc8",
        "1.0.0rc9",
        "1.0.1",
        "1.0.10",
        "1.0.11",
        "1.0.2",
        "1.0.3",
        "1.0.4",
        "1.0.5",
        "1.0.6",
        "1.0.7",
        "1.0.8",
        "1.0.9",
        "1.1.0",
        "1.1.1",
        "1.1.2",
        "1.1.3",
        "1.1.4",
        "1.10.0",
        "1.10.1",
        "1.10.2",
        "1.11.0",
        "1.11.1",
        "1.11.2",
        "1.12.0",
        "1.12.1",
        "1.13.0",
        "1.13.1",
        "1.13.2",
        "1.13.3",
        "1.13.4",
        "1.13.5",
        "1.15.0",
        "1.15.1",
        "1.15.2",
        "1.15.3",
        "1.15.4",
        "1.15.5",
        "1.15.6",
        "1.16.0",
        "1.17.0",
        "1.17.1",
        "1.18.0",
        "1.18.1",
        "1.19.0",
        "1.19.1",
        "1.2.0",
        "1.2.1",
        "1.2.2",
        "1.2.3",
        "1.21.0",
        "1.23.0",
        "1.23.1",
        "1.23.2",
        "1.23.3",
        "1.23.4",
        "1.23.5",
        "1.23.6",
        "1.24.0",
        "1.3.0",
        "1.4.0",
        "1.4.1",
        "1.5.0",
        "1.5.1",
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        "1.6.1",
        "1.6.2",
        "1.6.3",
        "1.6.4",
        "1.7.0",
        "1.7.0a1",
        "1.7.0a2",
        "1.8.0",
        "1.9.0",
        "2.0.0",
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        "2.0.0b1",
        "2.0.0rc0",
        "2.0.0rc1",
        "2.0.0rc2",
        "2.0.0rc3",
        "2.0.0rc4",
        "2.0.0rc5",
        "2.0.0rc6",
        "2.0.0rc7",
        "2.0.0rc8",
        "2.0.1",
        "2.0.2",
        "2.0.3",
        "2.0.4",
        "2.0.5",
        "2.0.6",
        "2.0.7",
        "2.1.0",
        "2.10.0",
        "2.10.1",
        "2.11.0",
        "2.11.1",
        "2.11.2",
        "2.12.0",
        "2.12.1",
        "2.12.2",
        "2.12.3",
        "2.12.4",
        "2.12.5",
        "2.13.0",
        "2.14.0",
        "2.14.1",
        "2.14.2",
        "2.15.0",
        "2.16.0",
        "2.17.0",
        "2.2.0",
        "2.2.1",
        "2.3.0",
        "2.4.0",
        "2.5.0",
        "2.6.0",
        "2.7.0",
        "2.7.1",
        "2.7.2",
        "2.7.3",
        "2.8.0",
        "2.9.0",
        "2.9.1"
      ]
    }
  ],
  "aliases": [
    "CVE-2025-61669",
    "GHSA-qh7q-6qm3-653w"
  ],
  "details": "Jupyter Server is the backend for Jupyter web applications. In jupyter_server versions through 2.17.0, the next query parameter in the login flow is insufficiently validated in `LoginFormHandler._redirect_safe()`, which allows redirects to arbitrary external domains via values such as `///example.com`. An attacker can use a crafted login URL to redirect users to a malicious site and facilitate phishing attacks. This issue is fixed in version 2.18.0.",
  "id": "PYSEC-2026-67",
  "modified": "2026-05-20T09:19:02.865171Z",
  "published": "2026-05-05T16:16:10.133Z",
  "references": [
    {
      "type": "EVIDENCE",
      "url": "https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-qh7q-6qm3-653w"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2025-61669 (GCVE-0-2025-61669)

Vulnerability from cvelistv5 – Published: 2026-05-05 15:28 – Updated: 2026-05-05 20:16

Title

jupyter_server next parameter open redirect can redirect users to external domains

Summary

Jupyter Server is the backend for Jupyter web applications. In jupyter_server versions through 2.17.0, the next query parameter in the login flow is insufficiently validated in `LoginFormHandler._redirect_safe()`, which allows redirects to arbitrary external domains via values such as `///example.com`. An attacker can use a crafted login URL to redirect users to a malicious site and facilitate phishing attacks. This issue is fixed in version 2.18.0.

Severity ?

6.3 (Medium)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N

CWE

CWE-601 - URL Redirection to Untrusted Site ('Open Redirect')

Assigner

GitHub_M

References

1 reference

URL	Tags
https://github.com/jupyter-server/jupyter_server/…	x_refsource_CONFIRM

Impacted products

1 product

Vendor	Product	Version
jupyter-server	jupyter_server	Affected: <= 2.17.0

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2025-61669",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-05T20:16:38.460105Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-05-05T20:16:59.332Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-qh7q-6qm3-653w"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "jupyter_server",
          "vendor": "jupyter-server",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c= 2.17.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Jupyter Server is the backend for Jupyter web applications. In jupyter_server versions through 2.17.0, the next query parameter in the login flow is insufficiently validated in `LoginFormHandler._redirect_safe()`, which allows redirects to arbitrary external domains via values such as `///example.com`. An attacker can use a crafted login URL to redirect users to a malicious site and facilitate phishing attacks. This issue is fixed in version 2.18.0."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 6.3,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "HIGH",
            "subIntegrityImpact": "NONE",
            "userInteraction": "PASSIVE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-601",
              "description": "CWE-601: URL Redirection to Untrusted Site (\u0027Open Redirect\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-05T15:28:43.833Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-qh7q-6qm3-653w",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-qh7q-6qm3-653w"
        }
      ],
      "source": {
        "advisory": "GHSA-qh7q-6qm3-653w",
        "discovery": "UNKNOWN"
      },
      "title": "jupyter_server next parameter open redirect can redirect users to external domains"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2025-61669",
    "datePublished": "2026-05-05T15:28:43.833Z",
    "dateReserved": "2025-09-29T20:25:16.180Z",
    "dateUpdated": "2026-05-05T20:16:59.332Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

GHSA-QH7Q-6QM3-653W

Vulnerability from github – Published: 2026-05-05 16:32 – Updated: 2026-05-08 13:48

Summary

Jupyter Server has an open redirection vulnerability in `next` query parameter

Details

Summary

The ?next=... URL query parameter has an open redirection vulnerability. In jupyter_server<=2.17.0, this URL query parameter allows redirection to arbitrary external domains, which can be exploited to facilitate phishing attacks on server users.

Details

The vulnerability is caused by insufficient validation in the LoginFormHandler._redirect_safe() method.

Source code reference: https://github.com/jupyter-server/jupyter_server/blob/987ebdd5e188cdc49751b01a0d6782d686492a53/jupyter_server/auth/login.py#L33-L76

This vulnerability was originally reported by Noriaki Iwasaki. All discovery credit goes to them.

PoC

Navigate to http://localhost:8888/login?next=///google.com
Observe that the user is redirected to google.com despite it being an external domain.

The external domain passed in the ?next parameter may be replaced with a malicious lookalike to facilitate phishing attacks. Jupyter Server deployments served on a public domain are especially vulnerable, as prod.company.com may be redirected to a look-alike URL such as prod.company.dev.

Impact

This vulnerability affects all users, especially enterprise users who work with sensitive/confidential data.

Patches

Jupyter Server 2.18+

Workaround

None.

Severity ?

6.0 (Medium)


                  
                    CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 2.17.0"
      },
      "package": {
        "ecosystem": "PyPI",
        "name": "jupyter-server"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.18.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2025-61669"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-601"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-05T16:32:48Z",
    "nvd_published_at": "2026-05-05T16:16:10Z",
    "severity": "MODERATE"
  },
  "details": "### Summary\n\nThe `?next=...` URL query parameter has an open redirection vulnerability. In `jupyter_server\u003c=2.17.0`, this URL query parameter allows redirection to arbitrary external domains, which can be exploited to facilitate phishing attacks on server users.\n\n### Details\n\nThe vulnerability is caused by insufficient validation in the `LoginFormHandler._redirect_safe()` method.\n\n- Source code reference: https://github.com/jupyter-server/jupyter_server/blob/987ebdd5e188cdc49751b01a0d6782d686492a53/jupyter_server/auth/login.py#L33-L76\n\nThis vulnerability was originally reported by Noriaki Iwasaki. All discovery credit goes to them.\n\n### PoC\n\n1. Navigate to `http://localhost:8888/login?next=///google.com`\n2. Observe that the user is redirected to `google.com` despite it being an external domain.\n\nThe external domain passed in the `?next` parameter may be replaced with a malicious lookalike to facilitate phishing attacks. Jupyter Server deployments served on a public domain are especially vulnerable, as `prod.company.com` may be redirected to a look-alike URL such as `prod.company.dev`. \n\n### Impact\n\nThis vulnerability affects all users, especially enterprise users who work with sensitive/confidential data.\n\n### Patches\n\nJupyter Server 2.18+\n\n### Workaround\n\nNone.",
  "id": "GHSA-qh7q-6qm3-653w",
  "modified": "2026-05-08T13:48:27Z",
  "published": "2026-05-05T16:32:48Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-qh7q-6qm3-653w"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-61669"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/jupyter-server/jupyter_server"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Jupyter Server has an open redirection vulnerability in `next` query parameter"
}

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.

Action not permitted

PYSEC-2026-67

CVE-2025-61669 (GCVE-0-2025-61669)

GHSA-QH7Q-6QM3-653W

Summary

Details

PoC

Impact

Patches

Workaround

Tags

Sightings

Nomenclature