UBUNTU-CVE-2025-59420

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Source
https://ubuntu.com/security/CVE-2025-59420
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-59420.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2025-59420
Upstream
Published
2025-09-22T18:15:00Z
Modified
2025-10-10T15:30:18Z
Severity
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to version 1.6.4, Authlib’s JWS verification accepts tokens that declare unknown critical header parameters (crit), violating RFC 7515 “must‑understand” semantics. An attacker can craft a signed token with a critical header (for example, bork or cnf) that strict verifiers reject but Authlib accepts. In mixed‑language fleets, this enables split‑brain verification and can lead to policy bypass, replay, or privilege escalation. This issue has been patched in version 1.6.4.

References

Affected packages

Ubuntu:22.04:LTS / python-authlib

Package

Name
python-authlib
Purl
pkg:deb/ubuntu/python-authlib@0.15.5-1?arch=source&distro=jammy

Affected ranges

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

Affected versions

0.*

0.15.4-1
0.15.5-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "python3-authlib",
            "binary_version": "0.15.5-1"
        }
    ]
}

Ubuntu:24.04:LTS / python-authlib

Package

Name
python-authlib
Purl
pkg:deb/ubuntu/python-authlib@1.3.0-1?arch=source&distro=noble

Affected ranges

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

Affected versions

1.*

1.2.1-1
1.3.0-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "python3-authlib",
            "binary_version": "1.3.0-1"
        }
    ]
}

Ubuntu:25.10 / python-authlib

Package

Name
python-authlib
Purl
pkg:deb/ubuntu/python-authlib@1.6.0-1?arch=source&distro=questing

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown 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"
        }
    ]
}

Ubuntu:25.04 / python-authlib

Package

Name
python-authlib
Purl
pkg:deb/ubuntu/python-authlib@1.5.1-1?arch=source&distro=plucky

Affected ranges

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

Affected versions

1.*

1.3.2-1
1.3.2-2
1.4.0-1
1.4.1-1
1.5.1-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "python3-authlib",
            "binary_version": "1.5.1-1"
        }
    ]
}