How serious is CVE-2026-28802?

This vulnerability has a CVSS score of 7.7 out of 10, classified as HIGH severity. Proof-of-concept exploit code is publicly available, making this an active threat.

Is there exploit code available for CVE-2026-28802?

Yes, proof-of-concept exploit code for CVE-2026-28802 is publicly available on GitHub and security research platforms. This increases the risk of active exploitation.

Which products are affected by CVE-2026-28802?

CVE-2026-28802 affects authlib authlib. Check the full CVE details for specific version information.

How do I fix CVE-2026-28802?

To remediate CVE-2026-28802, check for security patches from authlib. Apply all available updates and security patches. If no patch is available, implement recommended workarounds or security controls to mitigate the risk.

CVE-2026-28802

High

|7.7

Exploit Available

Plain English Summary

AI-powered analysis for quick understanding

This vulnerability allows an attacker to bypass security checks by sending a specially crafted JSON Web Token (JWT) that appears valid, even though it should be rejected. It affects versions of the Authlib library from 1.6.5 to just before 1.6.7, meaning any applications using these versions could be tricked into accepting unauthorized access without proper verification.

Technical 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 Vector Analysis

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

Confidentiality ImpactHigh

Integrity ImpactHigh

Availability ImpactHigh

ScopeChanged

Vector String

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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Exploit Resources

Search for proof-of-concept code and exploit modules

GitHub Search Exploit-DB Nuclei Templates Metasploit Vulners

Official References

NIST NVD

Est. Bounty

$2,474($1K-$5K)

Vendor Response

Grade APatched in 3 days

Quick Information

Published

Mar 6, 2026

about 1 month ago

Last Modified

Mar 9, 2026

29 days ago

Vendor

authlib

Product

authlib