CVE-2026-28802 — Authlib: Setting `alg: none` and a blank signature appears to bypass signature verification
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 containin…
Published: 2026-03-06 · CVSS: 7.7 · CVSS 4.0
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7