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Medium

Security advisory

Type: advisorySources: OSVCVE: CVE-2020-26244

Python oic is a Python OpenID Connect implementation. In Python oic before version 1.2.1, there are several related cryptographic issues affecting client implementations that use the library. The issues are: 1) The IdToken signature algorithm was not checked automatically, but only if the expected algorithm was passed in as a kwarg. 2) JWA `none` algorithm was allowed in all flows. 3) oic.consumer.Consumer.parse_authz returns an unverified IdToken. The verification of the token was left to the discretion of the implementator. 4) iat claim was not checked for sanity (i.e. it could be in the future). These issues are patched in version 1.2.1.

Products
Not specified
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2020-26244
Confirmed fixed CVEs
Not specified
Updated in this feed
31 Oct 2026, 11:08 UTC · Revision 1

Source evidence

CVE-2020-26244

core-osv · Original source

Published 2 Dec 2020, 20:15 UTC

Python oic is a Python OpenID Connect implementation. In Python oic before version 1.2.1, there are several related cryptographic issues affecting client implementations that use the library. The issues are: 1) The IdToken signature algorithm was not checked automatically, but only if the expected algorithm was passed in as a kwarg. 2) JWA `none` algorithm was allowed in all flows. 3) oic.consumer.Consumer.parse_authz returns an unverified IdToken. The verification of the token was left to the discretion of the implementator. 4) iat claim was not checked for sanity (i.e. it could be in the future). These issues are patched in version 1.2.1.

osv:CVE-2020-26244
Complete source record
{
  "id": "d359fd263fdedec695da8b4dd75ac20989c6dd955eba18f405e05be0d6489618",
  "url": "https://osv.dev/vulnerability/CVE-2020-26244",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2020-26244",
    "summary": "Python oic is a Python OpenID Connect implementation. In Python oic before version 1.2.1, there are several related cryptographic issues affecting client implementations that use the library. The issues are: 1) The IdToken signature algorithm was not checked automatically, but only if the expected algorithm was passed in as a kwarg. 2) JWA `none` algorithm was allowed in all flows. 3) oic.consumer.Consumer.parse_authz returns an unverified IdToken. The verification of the token was left to the discretion of the implementator. 4) iat claim was not checked for sanity (i.e. it could be in the future). These issues are patched in version 1.2.1.",
    "evidence": "osv:CVE-2020-26244",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2020-26244",
      "aliases": [
        "CVE-2020-26244",
        "GHSA-4fjv-pmhg-3rfg",
        "PYSEC-2020-69"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/CZ-NIC/pyoidc",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "0bf07d010e224247b6dc7bceb3c04aa328ed263e"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:python_openid_connect_project:python_openid_connect:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "1.2.1"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "1.2.0",
            "v1.1.2",
            "v1.1.1",
            "v1.1.0",
            "v1.0.0",
            "v0.15.0",
            "v0.14.0",
            "v0.13.0",
            "v0.12.0",
            "v0.11.1",
            "v0.11.0",
            "v0.10.0",
            "v0.9.5",
            "v0.9.4",
            "v0.9.1",
            "v0.9.0",
            "0.7.8",
            "v0.8.5",
            "0.7.7",
            "v0.7.6",
            "0.7.0",
            "v0.6.0",
            "0.5.0",
            "0.4"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-26244.json"
          }
        },
        {
          "ranges": [
            {
              "repo": "https://github.com/cz-nic/pyoidc",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "62f8d753fa17c8b1f29f8be639cf0b33afb02498"
                },
                {
                  "fixed": "0bf07d010e224247b6dc7bceb3c04aa328ed263e"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "fixed": "62f8d753fa17c8b1f29f8be639cf0b33afb02498"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "0bf07d010e224247b6dc7bceb3c04aa328ed263e"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "1.2.1"
                  }
                ]
              }
            }
          ],
          "versions": [
            "1.2.0",
            "v1.1.2",
            "v1.1.1",
            "v1.1.0",
            "v1.0.0",
            "v0.15.0",
            "v0.14.0",
            "v0.13.0",
            "v0.12.0",
            "v0.11.1",
            "v0.11.0",
            "v0.10.0",
            "v0.9.5",
            "v0.9.4",
            "v0.9.1",
            "v0.9.0",
            "0.7.8",
            "v0.8.5",
            "0.7.7",
            "v0.7.6",
            "0.7.0",
            "v0.6.0",
            "0.5.0",
            "0.4"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-26244.json"
          }
        }
      ],
      "modified": "2026-10-20T10:52:56.449413145Z",
      "provider": "osv",
      "references": [
        "https://github.com/OpenIDC/pyoidc/releases/tag/1.2.1",
        "https://github.com/OpenIDC/pyoidc/security/advisories/GHSA-4fjv-pmhg-3rfg",
        "https://github.com/OpenIDC/pyoidc/commit/62f8d753fa17c8b1f29f8be639cf0b33afb02498",
        "https://pypi.org/project/oic/"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2020-26244",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 384062,
  "published_at": "2020-12-02T20:15:13.43+00:00"
}