UBUNTU-CVE-2026-28802

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Source
https://ubuntu.com/security/CVE-2026-28802
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-28802.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-28802
Upstream
Published
2026-03-06T07:16:00Z
Modified
2026-09-11T15:00:28Z
Severity
  • 7.7 (High) CVSS_V4 - 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 CVSS Calculator
  • 9.1 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N CVSS Calculator
  • 9.8 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

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.

References

Affected packages

Ubuntu:25.10 / python-authlib

Package

Name
python-authlib
Purl
pkg:deb/ubuntu/python-authlib?arch=source&distro=questing

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

1.*
1.5.1-1
1.5.2-1
1.6.0-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "python3-authlib",
            "binary_version": "1.6.0-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-28802.json"