Authlib: Setting `alg: none` and a blank signature appears to bypass signature verification
Historical advisory recorded 23 Oct 2026 15:48:27 UTC. Read the latest advisory.
cve-program · CVE-2026-28802
PublishedAuthlib 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.
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cve-program · CVE-2026-28802
PublishedAuthlib: 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 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 published
- 6 Mar 2026 06:44:26 UTC
- Source modified
- 10 Sep 2026 12:05:07 UTC
- Saved here
- 23 Oct 2026 15:48:27 UTC
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- CVE Program Terms of Use
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Source: cve-program · CVE Program Terms of Use. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.
CVSS 4.0 · 7.7 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