{"cve":"CVE-2026-28802","nvd":{"published":"2026-03-06T07:16:01.053","modified":"2026-09-10T13:18:02.380","status":"Modified","description":"Authlib is a Python library which builds OAuth and OpenID Connect servers. From version 1.6.5 to before version 1.6.7, previous tests involving passing a malicious JWT containing alg: none and an empty signature was passing the signature verification step without any changes to the application code when a failure was expected.. This issue has been patched in version 1.6.7.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P","score":7.7},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8},"cwes":["CWE-347"],"references":["https://github.com/authlib/authlib/commit/a61c2acb807496e67f32051b5f1b1d5ccf8f0a75","https://github.com/authlib/authlib/commit/b87c32ed07b8ae7f805873e1c9cafd1016761df7","https://github.com/authlib/authlib/security/advisories/GHSA-7wc2-qxgw-g8gg","https://access.redhat.com/errata/RHSA-2026:19375","https://access.redhat.com/errata/RHSA-2026:4942"],"products":["authlib:authlib"],"source":"nvd","synced_at":"2026-10-19T22:25:53.701907451+00:00"},"epss":{"cve":"CVE-2026-28802","score":0.00503,"percentile":0.43059,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-7wc2-qxgw-g8gg","url":"https://osv.dev/vulnerability/GHSA-7wc2-qxgw-g8gg","summary":"Authlib: Setting `alg: none` and a blank signature appears to bypass signature verification","modified":"2026-09-10T03:50:38.043438200Z","packages":[{"ecosystem":"PyPI","name":"authlib","purl":"pkg:pypi/authlib","ranges":[">=1.6.5 <1.6.7"],"fixed":["1.6.7"]}]},{"id":"PYSEC-2026-2118","url":"https://osv.dev/vulnerability/PYSEC-2026-2118","summary":"","modified":"2026-07-13T07:15:15.458932241Z","packages":[{"ecosystem":"PyPI","name":"authlib","purl":"pkg:pypi/authlib","ranges":[">=1.6.5 <1.6.7"],"fixed":["1.6.7"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}