{"id":"CVE-2020-26244","aliases":["GHSA-4fjv-pmhg-3rfg","PYSEC-2020-69"],"url":"https://o3.security/vulnerability/CVE-2020-26244","summary":"Multiple cryptographic issues in Python oic","details":"### Impact\n* Client implementations using this library\n\n### Issues\n1) The IdToken signature algorithm was not checked automatically, but only if the expected algorithm was passed in as a kwarg.\n2) JWA `none` algorithm was allowed in all flows.\n3) `oic.consumer.Consumer.parse_authz` returns an unverified IdToken. The verification of the token was left to the discretion of the implementator.\n4) `iat` claim was not checked for sanity (i.e. it could be in the future)\n\n### Patches\n1) IdToken signature is now always checked.\n2) JWA `none` algorithm is now allowed only if using the `response_type` `code`\n3) IdToken verification is now done automatically.\n4) `iat` claim is now checked for sanity.","published":"2020-12-02T20:15:13.430Z","modified":"2026-10-05T10:26:50.414225879Z","cvss":{"score":6.8,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"PyPI","name":"oic","fixedVersion":"1.2.1"}],"fix":{"url":"https://github.com/OpenIDC/pyoidc/commit/62f8d753fa17c8b1f29f8be639cf0b33afb02498","label":"OpenIDC/pyoidc@62f8d75"},"references":[{"type":"ADVISORY","url":"https://github.com/OpenIDC/pyoidc/releases/tag/1.2.1"},{"type":"ADVISORY","url":"https://github.com/OpenIDC/pyoidc/security/advisories/GHSA-4fjv-pmhg-3rfg"},{"type":"FIX","url":"https://github.com/OpenIDC/pyoidc/commit/62f8d753fa17c8b1f29f8be639cf0b33afb02498"},{"type":"PACKAGE","url":"https://pypi.org/project/oic/"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2020-26244"},{"type":"PACKAGE","url":"https://github.com/OpenIDC/pyoidc"},{"type":"WEB","url":"https://github.com/pypa/advisory-database/tree/main/vulns/oic/PYSEC-2020-69.yaml"},{"type":"WEB","url":"https://pypi.org/project/oic"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-05T10:26:50.414225879Z"}}