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Fencer Vulns
high 8.8

CVE-2026-116672 json

Authlib RFC 7592 examples omit registration-access-token client binding

published 2026-10-27 12 d ago modified 2026-10-30 9 d ago also GHSA-c73q-w75p-j82v , EUVD-2026-111112

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 19%
public exploits
0
none known

Summary

Authlib is a Python library which builds OAuth and OpenID Connect servers. From 0.15 until 1.9.1, the documented ClientConfigurationEndpoint.authenticate_client and ClientConfigurationEndpoint.check_permission reference implementations look up a target client from request-controlled client_id data and check only whether that target is editable, without verifying that request.credential belongs to the target client. Deployments following both examples can allow a client holding any valid registration access token to read, modify, or delete another client's registration. Changing redirect_uris can enable authorization code or token interception, while deleting registrations can deny service to affected clients. This issue is fixed in version 1.9.1.

Patch / fix

  • pypi authlib 1.9.1
  • python-authlib Debian 14 1.9.1-1

debian advisories DEBIAN-CVE-2026-116672

  • python-Authlib openSUSE Tumbleweed 1.9.1-1.1

opensuse advisories openSUSE-SU-2026:12390-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-116672 updated cvss 8.8

authlib: authlib: Authorization bypass via missing client token verification

  • Red Hat Exploit Intelligence exploit-intelligence/vulnerability-analysis-rhel9 Red Hat Lightspeed Core lightspeed-core/lightspeed-stack-rhel9 Red Hat Migration Toolkit for Applications 8 mta/mta-solution-server-rhel9
    affected: workaround, no fix available
  • Red Hat OpenShift Lightspeed openshift-lightspeed/lightspeed-agentic-sandbox-rhel9
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Ansible Automation Platform 2 ansible-automation-platform-26/lightspeed-chatbot-rhel9, ansible-automation-platform-27/lightspeed-chatbot-rhel9 Red Hat OpenShift Virtualization 4 container-native-virtualization/ocp-virt-validation-checkup-rhel9 Red Hat Quay 3 quay/quay-rhel8, quay/quay-rhel9
    affected: workaround, no fix available
  • Red Hat Satellite 6.18 satellite/foreman-mcp-server-rhel9 1793272276
    fixed: vendor fix RHSA-2026:92667
  • Red Hat Satellite 6.19 satellite/foreman-mcp-server-rhel9 1793272279
    fixed: vendor fix RHSA-2026:92666
  • Red Hat Enterprise Linux command line assistant rhel-cla/rhel-knowledge-bridge-rhel10
    not affected: vulnerable code not in execute path

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
9 d ago

Exploit prediction

0.27% chance of exploitation in the next 30 days, higher than 19% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
GitHub 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
pypi authlib
>=0.15, <1.9.1
1.9.1

Affected products

  • authlib authlib

Classification

Weakness
  • CWE-639 Authorization Bypass Through User-Controlled Key
  • CWE-1188 Initialization of a Resource with an Insecure Default

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.