Is CVE-2026-28490 actively exploited?

CVE-2026-28490 has no public evidence of in-the-wild exploitation as of 2026-03-17.

What is the CVSS score for CVE-2026-28490?

CVE-2026-28490 has a CVSS score of 8.3 (HIGH severity). Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/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.

How do I patch CVE-2026-28490?

Patch guidance is available from authlib security advisories. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2026-28490.

Fix CVE-2026-28490 - HIGH authlib authlib

Description

Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to version 1.6.9, a cryptographic padding oracle vulnerability was identified in the Authlib Python library concerning the implementation of the JSON Web Encryption (JWE) RSA1_5 key management algorithm. Authlib registers RSA1_5 in its default algorithm registry without requiring explicit opt-in, and actively destroys the constant-time Bleichenbacher mitigation that the underlying cryptography library implements correctly. This issue has been patched in version 1.6.9.

CVSS Metrics

Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/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
Attack Vector: network
Complexity: high
Privileges: none
User Action: none
Confidentiality: undefined
Integrity: undefined
Availability: undefined
Weaknesses: CWE-203 CWE-327

Metadata

Primary Vendor: AUTHLIB
Published: 3/16/2026
Last Modified: 3/17/2026
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

Affected Products

authlib : authlib

Remediation Guidance

Executive Summary

Cite this page

CVE-2026-28490. CVEDatabase.com. Retrieved 1 May 2026. https://cvedatabase.com/cve/CVE-2026-28490

View on NIST NVD

CVE-2026-28490 vulnerability