Description
Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to 1.9.1, Authlib's OctKey.import_key() and HMAC signing and verification path accept zero-length key material. If an application's secret lookup can return an empty string or empty bytes, a remote attacker can compute the deterministic HS256, HS384, or HS512 signature for arbitrary token claims and have Authlib treat the token as authentic. This issue is fixed in version 1.9.1.
Published: 2026-10-22
Score: 7.4 High
EPSS: < 1% Very Low
KEV: No
AI Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Remediation

No solution or workaround provided in the CVE record.

Additional remediation guidance may be available on OpenCVE Cloud.

Tracking

Sign in to view the affected projects.

Advisories

No advisories yet.

History

Fri, 23 Oct 2026 12:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-347
References
Metrics threat_severity

None

threat_severity

Important


Fri, 23 Oct 2026 03:45:00 +0000

Type Values Removed Values Added
First Time appeared Authlib
Authlib authlib
Vendors & Products Authlib
Authlib authlib

Fri, 23 Oct 2026 00:45:00 +0000

Type Values Removed Values Added
Description Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to 1.9.1, Authlib's OctKey.import_key() and HMAC signing and verification path accept zero-length key material. If an application's secret lookup can return an empty string or empty bytes, a remote attacker can compute the deterministic HS256, HS384, or HS512 signature for arbitrary token claims and have Authlib treat the token as authentic. This issue is fixed in version 1.9.1.
Title Authlib accepts an empty HMAC key, allowing JWS/JWT signature forgery (HS256/HS384/HS512)
Weaknesses CWE-1391
CWE-287
CWE-326
References
Metrics cvssV3_1

{'score': 7.4, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-10-22T21:14:03.060Z

Reserved: 2026-10-21T20:34:25.600Z

Link: CVE-2026-114616

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-22T22:18:04.420

Modified: 2026-10-22T22:18:04.420

Link: CVE-2026-114616

cve-icon Redhat

Severity : Important

Publid Date: 2026-10-22T21:14:03Z

Links: CVE-2026-114616 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-10-23T13:30:07Z

Weaknesses
  • CWE-1391

    Use of Weak Credentials

  • CWE-287

    Improper Authentication

  • CWE-326

    Inadequate Encryption Strength

  • CWE-347

    Improper Verification of Cryptographic Signature