VDB-349411 · CVE-2026-28802 · GHSA-7wc2-qxgw-g8gg

Authlib up to 1.6.6 JWT signature verification

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7.4	$0-$5k	0.00

Summaryinfo

A vulnerability classified as problematic has been found in Authlib up to 1.6.6. The impacted element is an unknown function of the component JWT Handler. This manipulation causes signature verification. This vulnerability is handled as CVE-2026-28802. The attack can be initiated remotely. There is not any exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability has been found in Authlib up to 1.6.6 and classified as problematic. Affected by this vulnerability is some unknown processing of the component JWT Handler. The manipulation with an unknown input leads to a signature verification vulnerability. The CWE definition for the vulnerability is CWE-347. The product does not verify, or incorrectly verifies, the cryptographic signature for data. As an impact it is known to affect integrity. The summary by CVE is:

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.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-28802 since 03/03/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. The technical details are unknown and an exploit is not publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 301403 (Linux Distros Unpatched Vulnerability : CVE-2026-28802), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 1.6.7 eliminates this vulnerability. Applying the patch a61c2acb807496e67f32051b5f1b1d5ccf8f0a75 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (301403) and CERT Bund (WID-SEC-2026-0935). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

Red Hat Ansible Automation Platform
Debian Linux
Amazon Linux 2
Red Hat Enterprise Linux
Fedora Linux
SUSE Linux
Oracle Linux
RESF Rocky Linux
HCL BigFix
IBM DB2
IBM App Connect Enterprise
Red Hat OpenShift

Productinfo

Name

Authlib

Version

License

open-source

Website

Product: https://github.com/authlib/authlib/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 7.6
VulDB Meta Temp Score: 7.4

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 9.8
NVD Vector: 🔒

CVSSv2info

AV	AC	Au	C	I	A
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💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Signature verification
CWE: CWE-347 / CWE-345
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 301403
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-28802

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Authlib 1.6.7
Patch: a61c2acb807496e67f32051b5f1b1d5ccf8f0a75

Timelineinfo

03/03/2026 CVE reserved
03/06/2026 +3 days Advisory disclosed
03/06/2026 +0 days VulDB entry created
07/01/2026 +117 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: GHSA-7wc2-qxgw-g8gg
Status: Confirmed

CVE: CVE-2026-28802 (🔒)
GCVE (CVE): GCVE-0-2026-28802
GCVE (VulDB): GCVE-100-349411
CERT Bund: WID-SEC-2026-0935 - Red Hat Ansible Automation Platform: Mehrere Schwachstellen

Entryinfo

Created: 03/06/2026 08:40
Updated: 07/01/2026 18:12
Changes: 03/06/2026 08:40 (68), 03/07/2026 14:04 (2), 03/08/2026 08:08 (1), 04/02/2026 20:47 (7), 04/15/2026 23:30 (1), 06/10/2026 06:42 (1), 07/01/2026 18:12 (12)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.