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Fencer Vulns
high 8.4

CVE-2026-118669 json

OAuthLib: Token grants can use attacker-supplied client_id for authorization after authenticating a different client

published 2026-10-28 11 d ago modified 2026-11-03 5 d ago also GHSA-7984-qgvg-3j9c , EUVD-2026-112488

cvss
8.4
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 24%
public exploits
0
none known

Summary

OAuthLib is an implementation of the OAuth request-signing logic for Python 3.6+. Prior to 4.0.0, the client_credentials and Resource Owner Password Credentials token grant handlers can authenticate request.client as one confidential client while retaining an attacker-supplied request.client_id for validate_grant_type and validate_scopes. A lower-privilege authenticated client can therefore cause grant and scope authorization to use another client's identity when an application validator relies on the documented client_id argument, potentially issuing tokens with unauthorized grants or scopes. Validators that authorize exclusively from request.client may not be affected. This issue is fixed in version 4.0.0.

Patch / fix

  • pypi oauthlib 4.0.0

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-2026-118669 updated cvss 8.1

oauthlib: oauthlib: privilege escalation via client identity confusion in token grant handlers

  • Red Hat Confidential Compute Attestation openshift-sandboxed-containers/osc-podvm-builder-rhel9 Red Hat Fence Agents Remediation Operator workload-availability/fence-agents-remediation-rhel9-operator Red Hat Lightspeed Core lightspeed-core/lightspeed-stack-rhel9 Red Hat Lightspeed Services for Advanced Cluster Management lightspeed-services-acm/ocp-rules-rhel9 Red Hat Migration Toolkit for Applications 8 mta/mta-rhel9-operator
    affected: no fix available
  • Red Hat Migration Toolkit for Containers rhmtc/openshift-migration-rhel8-operator
    affected: no fix planned “Will not fix”
  • Red Hat Migration Toolkit for Virtualization migration-toolkit-virtualization/mtv-rhel9-operator Red Hat OpenShift Lightspeed openshift-lightspeed/lightspeed-service-api-rhel9, openshift-lightspeed/lightspeed-agentic-sandbox-rhel9, openshift-lightspeed/lightspeed-to-dataverse-exporter-rhel9 Red Hat AI Inference Server rhaii/vllm-cpu-rhel9, rhaii/vllm-tpu-rhel9, rhaii/vllm-cuda-rhel9, rhaii-fast/vllm-cpu-rhel9, rhaii-fast/vllm-tpu-rhel9, rhaii-fast/vllm-cuda-rhel9
    affected: no fix available
  • Red Hat Ansible Automation Platform 2 python-oauthlib 3.1.1-2.el8pc, python3.11-oauthlib 3.2.2-1.el9ap, python3.12-oauthlib 3.2.2-2.el9ap, automation-controller 4.7.18-1.el9ap, ansible-automation-platform-26/hub-rhel9, ansible-automation-platform-27/hub-rhel9, +43 more
    affected: no fix available “Fix deferred”
  • Red Hat Enterprise Linux 8 fence-agents, fence-agents-all, fence-agents-apc, fence-agents-aws, fence-agents-eps, fence-agents-gce, +44 more Red Hat Enterprise Linux 9 fence-virt, fence-virtd, fence-agents, fence-virtd-cpg, fence-virtd-tcp, fence-agents-all, +52 more Red Hat Enterprise Linux 10 python-oauthlib 3.1.1-2.el8pc Red Hat Enterprise Linux AI (RHEL AI) 3 rhelai3/bootc-cuda-rhel9, rhelai3/bootc-aws-cuda-rhel9, rhelai3/bootc-gcp-cuda-rhel9, rhelai3/bootc-azure-cuda-rhel9 Red Hat Lightspeed Services for OCP lightspeed-services-ocp/ocp-rules-rhel9 Red Hat OpenShift AI (RHOAI) rhoai/rhai-cli-rhel9, rhoai/odh-automl-rhel9, rhoai/odh-autorag-rhel9, rhoai/odh-feature-server-rhel9, rhoai/odh-llama-stack-core-rhel9, rhoai/odh-th-torch-cpu-py312-rhel9, +25 more
    +5 more products
    Red Hat OpenShift Container Platform 4 python-oauthlib 3.1.1-2.el8pc, openshift4/ose-ansible-rhel9-operator Red Hat OpenShift Container Platform 5 openshift5/ose-ansible-rhel9-operator Red Hat OpenShift Virtualization 4 container-native-virtualization/ocp-virt-validation-checkup-rhel9 Red Hat Quay 3 quay/quay-rhel8, quay/quay-rhel9 Red Hat Satellite 6 satellite/iop-advisor-backend-rhel9
    affected: no fix available
  • Red Hat Discovery 2 discovery/discovery-server-rhel9 1793734080
    fixed: vendor fix RHSA-2026:94802
  • Red Hat OpenShift Service Mesh 3 openshift-service-mesh/kiali-rhel9-operator
    not affected: vulnerable code not in execute path
  • Red Hat Pen Drive Powered by Red Hat Lightspeed pen-drive/pen-drive-scanner-rhel9 Red Hat Advanced Cluster Management for Kubernetes 2 rhacm2/volsync-rhel9, rhacm2/volsync-operator-bundle
    not affected: vulnerable code not present
show 4 more
  • Red Hat Ansible Automation Platform 2 ansible-automation-platform-26/lightspeed-rhel9, ansible-automation-platform-27/lightspeed-rhel9, ansible-automation-platform-26/eda-controller-rhel9, ansible-automation-platform-27/eda-controller-rhel9, ansible-automation-platform-26/eda-controller-rhel9-operator, ansible-automation-platform-27/eda-controller-rhel9-operator
    not affected: component not present
  • Red Hat Discovery 2 discovery/discovery-ui-rhel9 1793733716
    not affected: vulnerable code not present
  • Red Hat OpenShift AI (RHOAI) rhoai/odh-mlflow-rhel9, rhoai/odh-kserve-agent-rhel9, rhoai/odh-kserve-router-rhel9, rhoai/odh-kserve-controller-rhel9, rhoai/odh-th06-cpu-torch291-py312-rhel9, rhoai/odh-th06-cuda130-torch291-py312-rhel9
    not affected: component not present
  • Red Hat Service Telemetry Framework 1.5 stf/smart-gateway-rhel9-operator, stf/service-telemetry-rhel9-operator
    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
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
5 d ago

Exploit prediction

0.31% chance of exploitation in the next 30 days, higher than 24% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/oauthlib/oauthlib/security/advisories/GHSA-7984-qgvg-3j9c referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 8.4 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:H/SI:H/SA:N
CNA 4.0 8.4 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected packages

ecosystem package affected fixed in
pypi oauthlib
<4.0.0
4.0.0

Affected products

  • oauthlib oauthlib

Classification

Weakness

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.