CVE-2024-37568: Authlib Authlib Has Algorithm Confusion With Vulnerability

HIGH
Advisory Identifier: GHSA-5357-c2jx-v7qh
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CVSS 7.4
CWE-284 CWE-327 CWE-347
Published
Advisory Summary

CVE-2024-37568 is a HIGH (CVSS 7.4) authlib has algorithm confusion with vulnerability (CWE-284: Improper Access Control) affecting Authlib libraries in the PyPI ecosystem. The issue involves authlib has algorithm confusion with asymmetric public keys. Remediation is available by upgrading affected packages to version 1.3.1.

CVE-2024-37568 at a Glance

CVE Identifier CVE-2024-37568
GHSA Identifier GHSA-5357-c2jx-v7qh
Severity HIGH
CVSS v3.1 Base Score 7.4
CWE Classification CWE-284: Improper Access Control
Affected Product Authlib
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 7.4

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability None (A:N)

How to Fix CVE-2024-37568

To remediate this vulnerability, upgrade all affected Authlib dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

authlib fixed: 1.3.1 
pip install authlib>=1.3.1
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show authlib

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2024-37568, inspect your installed packages using pip:

pip show authlib

Analyze the terminal output to locate any version of Authlib in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.3.1), your application is affected.

Note: The pip show authlib command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-284: Improper Access Control, where the product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. In Authlib, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

lepture Authlib before 1.3.1 has algorithm confusion with asymmetric public keys. Unless an algorithm is specified in a jwt.decode call, HMAC verification is allowed with any asymmetric public key. (This is similar to CVE-2022-29217 and CVE-2024-33663.)

CVE-2024-37568 Affected Authlib Versions

1 component(s)
Fixed Versions:
1.3.1
Product / Package Ecosystem Affected Versions Fixed Version
authlib
pypi/authlib
PyPI
< 1.3.1
1.3.1

References

NVD — CVE-2024-37568 NVD
https://nvd.nist.gov/vuln/detail/CVE-2024-37568
Authlib Source Repository REPOSITORY
https://github.com/lepture/authlib/issues/654
Authlib Source Repository REPOSITORY
https://github.com/lepture/authlib
Authlib Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/authlib/PYSEC-2024-52.yaml
lists.debian.org/debian-lts-announce... WEB
https://lists.debian.org/debian-lts-announce/2025/10/msg00032.html
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FHJI32SN4FNAUVNALVGOKWHNSQ6XS3M5
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IZI7HYGN7VZAYFV6UV3SRLYF7QGERXIU
www.vicarius.io/vsociety/posts/algo... WEB
https://www.vicarius.io/vsociety/posts/algorithm-confusion-in-lepture-authlib-cve-2024-37568

Frequently Asked Questions

What is CVE-2024-37568?
CVE-2024-37568 is a security vulnerability in Authlib involving Authlib has algorithm confusion with asymmetric public keys under CWE-284: Improper Access Control.
Which Authlib versions are affected?
Affected versions include releases prior to 1.3.1 across affected packages: authlib.
What version fixes CVE-2024-37568?
Upgrading to 1.3.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is authlib affected?
Yes, authlib is affected in releases prior to 1.3.1. Upgrade your dependency to 1.3.1 or later.
What is the CVSS score of CVE-2024-37568?
CVE-2024-37568 has a CVSS v3.1 base score of 7.4 (HIGH) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N.
What CWE is associated with CVE-2024-37568?
CVE-2024-37568 is classified under CWE-284: Improper Access Control (The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.).
How can I check PyPI dependencies for CVE-2024-37568?
Run the dependency tree command: 'pip show authlib'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-5357-c2jx-v7qh",
  "modified" : "2025-11-03T18:31:14Z",
  "published" : "2024-06-09T21:30:33Z",
  "aliases" : [ "CVE-2024-37568" ],
  "summary" : "Authlib has algorithm confusion with asymmetric public keys",
  "details" : "lepture Authlib before 1.3.1 has algorithm confusion with asymmetric public keys. Unless an algorithm is specified in a jwt.decode call, HMAC verification is allowed with any asymmetric public key. (This is similar to CVE-2022-29217 and CVE-2024-33663.)",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "authlib"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.3.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2024-37568"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/lepture/authlib/issues/654"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/lepture/authlib"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/authlib/PYSEC-2024-52.yaml"
  }, {
    "type" : "WEB",
    "url" : "https://lists.debian.org/debian-lts-announce/2025/10/msg00032.html"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FHJI32SN4FNAUVNALVGOKWHNSQ6XS3M5"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IZI7HYGN7VZAYFV6UV3SRLYF7QGERXIU"
  }, {
    "type" : "WEB",
    "url" : "https://www.vicarius.io/vsociety/posts/algorithm-confusion-in-lepture-authlib-cve-2024-37568"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-284", "CWE-327", "CWE-347" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2024-06-10T15:59:18Z",
    "nvd_published_at" : "2024-06-09T19:15:52Z"
  }
}