DEBIAN-CVE-2026-27962

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Source
https://security-tracker.debian.org/tracker/CVE-2026-27962
Import Source
https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-27962.json
JSON Data
https://api.osv.dev/v1/vulns/DEBIAN-CVE-2026-27962
Upstream
Published
2026-03-16T18:16:07.383Z
Modified
2026-03-17T09:00:13.918667Z
Severity
  • 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
Summary
[none]
Details

Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to version 1.6.9, a JWK Header Injection vulnerability in authlib's JWS implementation allows an unauthenticated attacker to forge arbitrary JWT tokens that pass signature verification. When key=None is passed to any JWS deserialization function, the library extracts and uses the cryptographic key embedded in the attacker-controlled JWT jwk header field. An attacker can sign a token with their own private key, embed the matching public key in the header, and have the server accept the forged token as cryptographically valid — bypassing authentication and authorization entirely. This issue has been patched in version 1.6.9.

References

Affected packages

Debian:11 / python-authlib

Package

Name
python-authlib
Purl
pkg:deb/debian/python-authlib?arch=source

Affected ranges

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

Affected versions

0.*
0.15.4-1
0.15.4-1+deb11u1
0.15.4-2
0.15.5-1
1.*
1.0.0-1
1.0.1-1
1.1.0-1
1.1.0-2
1.2.0-1
1.2.1-1
1.3.0-1
1.3.0-2
1.3.0-3
1.3.1-1
1.3.2-1
1.3.2-2
1.4.0-1
1.4.1-1
1.5.0-1
1.5.1-1
1.5.2-1
1.6.0-1
1.6.1-1
1.6.3-1
1.6.4-1
1.6.5-1
1.6.6-1
1.6.7-1
1.6.8-1
1.6.9-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Database specific

source 
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-27962.json"

Debian:12 / python-authlib

Package

Name
python-authlib
Purl
pkg:deb/debian/python-authlib?arch=source

Affected ranges

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

Affected versions

1.*
1.2.0-1
1.2.1-1
1.3.0-1
1.3.0-2
1.3.0-3
1.3.1-1
1.3.2-1
1.3.2-2
1.4.0-1
1.4.1-1
1.5.0-1
1.5.1-1
1.5.2-1
1.6.0-1
1.6.1-1
1.6.3-1
1.6.4-1
1.6.5-1
1.6.6-1
1.6.7-1
1.6.8-1
1.6.9-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Database specific

source 
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-27962.json"

Debian:13 / python-authlib

Package

Name
python-authlib
Purl
pkg:deb/debian/python-authlib?arch=source

Affected ranges

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

Affected versions

1.*
1.6.0-1
1.6.1-1
1.6.3-1
1.6.4-1
1.6.5-1
1.6.6-1
1.6.7-1
1.6.8-1
1.6.9-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Database specific

source 
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-27962.json"

Debian:14 / python-authlib

Package

Name
python-authlib
Purl
pkg:deb/debian/python-authlib?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
1.6.9-1

Affected versions

1.*
1.6.0-1
1.6.1-1
1.6.3-1
1.6.4-1
1.6.5-1
1.6.6-1
1.6.7-1
1.6.8-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Database specific

source 
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-27962.json"