← Back to CVE Explorer

CVE-2026-101274

Full vulnerability record from the local CVENow database.

Description

When pretix is used as the identity provider in a Single-Sign-On (SSO) setup for customer accounts, the system did not properly validate the `response_type` requested in an authorization request against the configured grant type of the SSO client. This means that if an SSO client was configured to only allow the `code` response type, which requires knowledge of the client secret to use and would wrongfully send a response type like `id_token`, it would receive back a valid token. Exploiting this requires the attacker to run JavaScript on the page specified by `redirect_uri`, which must be from a list specified in the client configuration.

Severity
MEDIUM
CVSS score
6.9 (v4.0)
Vulnerability status
Deferred
Source identifier
655498c3-6ec5-4f0b-aea6-853b334d05a6
Published
2026-10-28 11:17:13.577000
Last modified
2026-10-28 15:24:56.033000
View original CVE JSON
{
  "id": "CVE-2026-101274",
  "sourceIdentifier": "655498c3-6ec5-4f0b-aea6-853b334d05a6",
  "published": "2026-10-28T11:17:13.577",
  "lastModified": "2026-10-28T15:24:56.033",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "When pretix is used as the identity provider in a Single-Sign-On (SSO) setup for customer accounts, the system did not properly validate the `response_type` requested in an authorization request against the configured grant type of the SSO client. This means that if an SSO client was configured to only allow the `code` response type, which requires knowledge of the client secret to use and would wrongfully send a response type like `id_token`, it would receive back a valid token. Exploiting this requires the attacker to run JavaScript on the page specified by `redirect_uri`, which must be from a list specified in the client configuration."
    }
  ],
  "affected": [
    {
      "source": "655498c3-6ec5-4f0b-aea6-853b334d05a6",
      "affectedData": [
        {
          "vendor": "pretix",
          "defaultStatus": "unaffected",
          "collectionURL": "https://pypi.python.org",
          "packageName": "pretix",
          "repo": "https://github.com/pretix/pretix",
          "versions": [
            {
              "version": "0",
              "lessThan": "2026.6.4",
              "versionType": "python",
              "status": "affected"
            },
            {
              "version": "2026.7.0",
              "lessThan": "2026.7.3",
              "versionType": "python",
              "status": "affected"
            },
            {
              "version": "2026.8.0",
              "lessThan": "2026.8.1",
              "versionType": "python",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV40": [
      {
        "source": "655498c3-6ec5-4f0b-aea6-853b334d05a6",
        "type": "Secondary",
        "cvssData": {
          "version": "4.0",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:L/VA:N/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "baseScore": 6.9,
          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "attackRequirements": "PRESENT",
          "privilegesRequired": "HIGH",
          "userInteraction": "PASSIVE",
          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "LOW",
          "vulnAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "HIGH",
          "subIntegrityImpact": "NONE",
          "subAvailabilityImpact": "NONE",
          "exploitMaturity": "NOT_DEFINED",
          "confidentialityRequirement": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "availabilityRequirement": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "valueDensity": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "providerUrgency": "NOT_DEFINED"
        }
      }
    ]
  },
  "references": [
    {
      "url": "https://pretix.eu/about/en/blog/20261028-release-2026-8-1/",
      "source": "655498c3-6ec5-4f0b-aea6-853b334d05a6"
    }
  ]
}