---
id: CVE-2026-28802
title: Authlib is a Python library which builds OAuth and OpenID Connect servers
summary: >-
  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…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-347
vendor: authlib
product: authlib
affected:
  - 'authlib >= 1.6.5, < 1.6.7'
patched:
  - authlib 1.6.7
published: '2026-03-06'
updated: '2026-09-10'
sourceUpdated: '2026-09-10T13:18:02.380'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-28802'
references:
  - url: >-
      https://github.com/authlib/authlib/commit/a61c2acb807496e67f32051b5f1b1d5ccf8f0a75
    label: security-advisories@github.com
  - url: >-
      https://github.com/authlib/authlib/commit/b87c32ed07b8ae7f805873e1c9cafd1016761df7
    label: security-advisories@github.com
  - url: 'https://github.com/authlib/authlib/security/advisories/GHSA-7wc2-qxgw-g8gg'
    label: security-advisories@github.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:19375'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:4942'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:5168'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:5665'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:6309'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:6568'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/security/cve/CVE-2026-28802'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2445120'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-28802.json
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-28802'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-28802'
  - url: 'https://github.com/authlib/authlib'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
  - osv
  - pip
  - score-dispute
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-03-06T16:00:04.267898Z'
scores:
  nvd: 9.8
  cna: 7.7
  vendor: 9.1
epss: 0.00425
epssPercentile: 0.36293
ingestedAt: '2026-07-01T15:50:58.581Z'
aliases:
  - GHSA-7wc2-qxgw-g8gg
  - PYSEC-2026-2118
ecosystem: pip
---

## Overview

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.

## Affected

- `authlib >= 1.6.5, < 1.6.7`

## Remediation

Upgrade past the affected range:

- `authlib 1.6.7`

## Vendor advisories

- **RHSA-2026:6309** · Red Hat · fixed in: Red Hat Ansible Automation Platform 2.6 · released 2026-03-31 · [advisory](https://access.redhat.com/errata/RHSA-2026:6309)
- **RHSA-2026:5665** · Red Hat · fixed in: Red Hat Quay 3.10 · released 2026-03-24 · [advisory](https://access.redhat.com/errata/RHSA-2026:5665)
- **RHSA-2026:4942** · Red Hat · fixed in: Red Hat Quay 3.12 · released 2026-03-18 · [advisory](https://access.redhat.com/errata/RHSA-2026:4942)
- **RHSA-2026:6568** · Red Hat · fixed in: Red Hat Quay 3.15 · released 2026-04-03 · [advisory](https://access.redhat.com/errata/RHSA-2026:6568)
- **RHSA-2026:19375** · Red Hat · fixed in: Red Hat Quay 3.16 · released 2026-05-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:19375)
- **RHSA-2026:5168** · Red Hat · fixed in: Red Hat Quay 3.9 · released 2026-03-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:5168)
- **Red Hat VEX** · Important · affected: Red Hat Satellite 6 · no fix planned: Red Hat Satellite 6 · updated 2026-09-09 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-28802.json)

## Package advisory (CVE-2026-28802)

Affected packages:

- `authlib >= 1.6.5, < 1.6.7`

Patched in:

- `authlib 1.6.7`

Source: https://osv.dev/vulnerability/GHSA-7wc2-qxgw-g8gg