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Fencer Vulns
high 7.5

CVE-2026-18446 json

fast-uri vulnerable to host confusion via backslash authority introducer

published 2026-07-31 3 mo ago modified 2026-09-10 1 mo ago also GHSA-7p8r-x3mc-p8w7 , EUVD-2026-51553

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 32%
public exploits
0
none known

Summary

fast-uri before 4.1.2, 3.1.5, and 2.4.4 requires a literal double forward slash to recognize a URI authority, so a reference that uses a backslash based introducer in place of it (backslash backslash, forward slash backslash, or backslash forward slash) is parsed with no authority and folds into the path. Node's native WHATWG URL parser instead treats a backslash as interchangeable with a forward slash for special schemes, so the two parsers extract different hosts from the same input. Applications that use fast-uri to enforce host based policy such as allowlists, SSRF filtering, or redirect validation before passing the same URL into Node's URL or fetch consumers can be steered to an unintended host. Upgrade to fast-uri 4.1.2, 3.1.5, or 2.4.4.

Patch / fix

  • npm fast-uri 2.4.4, 3.1.5, 4.1.2
  • fast-uri fast-uri 2.4.4, 3.1.5, 4.1.2
  • node-ajv Debian 14 8.20.0~ds+~cs7.1.3-1

debian advisories DEBIAN-CVE-2026-18446

  • grafana13.1 hummingbird 1 13.1.1-0.4.hum1
  • grafana12.4 hummingbird 1 12.4.6-0.3.hum1

red hat advisories RHSA-2026:49387RHSA-2026:49401

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-2026-18446 updated cvss 7.5

fast-uri: fast-uri: Host confusion vulnerability via backslash in URI authority

  • Red Hat Migration Toolkit for Applications 8 mta/mta-solution-server-rhel9 Red Hat OpenShift Serverless openshift-serverless-1/kn-eventing-integrations-transform-jsonata-rhel9 Red Hat build of Apache Camel - HawtIO 4 rhaf-hawtio-maven-repository.zip 4.4.0.GA Red Hat build of Apicurio Registry 3 apicurio/apicurio-registry-ui-rhel8, apicurio/apicurio-registry-ui-rhel9 Red Hat Build of Podman Desktop rh-podman-desktop 3c6fc75a2a6cf5bb9b8a667fddcbbf428132badc Red Hat Connectivity Link 1 rhcl-1/rhcl-console-plugin-rhel9
    affected: workaround, no fix available
  • Red Hat Edge Manager 1 rhem/flightctl-ui-rhel9
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Enterprise Linux 9 sgx-mpa, tdx-qgs, sgx-libs, sgx-pccs, sgx-common, sgx-pccs-admin, +2 more Red Hat Enterprise Linux 10 linux-sgx 2.26-7.el10
    affected: workaround, no fix available
  • Red Hat Enterprise Linux AI (RHEL AI) 3 rhelai3/bootc-cuda-rhel9, rhelai3/bootc-rocm-rhel9, rhelai3/bootc-gaudi-rhel9, rhelai3/disk-image-cuda-rhel9
    affected: workaround, no fix available, no fix planned “Will not fix”
  • Red Hat OpenShift AI (RHOAI) rhoai/odh-core-bff-rhel9, rhoai/odh-dashboard-operator-rhel9, rhoai/odh-mod-arch-agent-ops-rhel9, rhoai/odh-workbench-codeserver-datascience-cpu-py312-rhel9 Red Hat OpenShift Container Platform 4 openshift4/ose-console-rhel9 Red Hat OpenShift Container Platform 5 openshift5/ose-console-rhel9, openshift5/nmstate-console-plugin-rhel9 Red Hat Openshift Data Foundation 4 odf4/mcg-core-rhel9, odf4/odf-console-rhel9, odf4/ocs-client-console-rhel9, odf4/odf-multicluster-console-rhel9 Red Hat OpenShift Dev Spaces devspaces/code-rhel9 Red Hat Satellite 6 nodejs-mini-css-extract-plugin 2.10.2-2.2.el10sat, nodejs-compression-webpack-plugin 10.0.0-3.2.el10sat
    affected: workaround, no fix available
  • Red Hat Hardened Images grafana12.4 12.4.6-0.3.hum1, grafana13.1 13.1.1-0.4.hum1
    fixed: vendor fix RHSA-2026:49401
  • Red Hat OpenShift AI 2.25 rhoai/odh-dashboard-rhel9 1791853525, rhoai/odh-mod-arch-model-registry-rhel9 1791853432
    fixed: vendor fix RHSA-2026:87410
  • Red Hat OpenShift AI 3.4 rhoai/odh-dashboard-rhel9 1791861020, rhoai/odh-mod-arch-maas-rhel9 1791860708, rhoai/odh-feature-server-rhel9 1791863220, rhoai/odh-mod-arch-automl-rhel9 1791861032, rhoai/odh-mod-arch-gen-ai-rhel9 1793001896, rhoai/odh-mod-arch-mlflow-rhel9 1791861383, +3 more
    fixed: vendor fix RHSA-2026:84734
show 10 more
  • Red Hat OpenShift Container Platform 4.16 openshift4/ose-monitoring-plugin-rhel9 1788235712
    fixed: vendor fix RHSA-2026:62550
  • Red Hat OpenShift Container Platform 4.21 openshift4/nmstate-console-plugin-rhel9 1789592806
    fixed: vendor fix RHSA-2026:68547
  • Red Hat OpenShift Container Platform 4.22 openshift4/nmstate-console-plugin-rhel9 1789567849, openshift4/ose-agent-installer-ui-rhel9 1790130874
    fixed: vendor fix RHSA-2026:68553
  • Red Hat Cost Management On Premise costmanagement/costmanagement-ui-rhel10
    not affected: vulnerable code not present
  • Red Hat Cryostat 4 grafana-infinity-datasource-npm, cryostat-openshift-console-plugin-npm, cryostat/cryostat-openshift-console-plugin-rhel9
    not affected: component not present
  • Red Hat Migration Toolkit for Containers rhmtc/openshift-migration-ui-rhel8 Red Hat Multicluster Engine for Kubernetes multicluster-engine/console-mce-rhel9 Red Hat Network Observability Operator network-observability/network-observability-console-plugin-rhel9, network-observability/network-observability-console-plugin-pf5-rhel9 Red Hat OpenShift Lightspeed openshift-lightspeed/lightspeed-console-plugin-rhel9, openshift-lightspeed/lightspeed-agentic-console-rhel9, openshift-lightspeed/lightspeed-console-plugin-419-rhel9, openshift-lightspeed/lightspeed-console-plugin-pf5-rhel9 Red Hat OpenShift Pipelines openshift-pipelines/pipelines-hub-ui-rhel8, openshift-pipelines/pipelines-hub-ui-rhel9, openshift-pipelines/pipelines-console-plugin-rhel8, openshift-pipelines/pipelines-console-plugin-rhel9, openshift-pipelines/pipelines-console-plugin-pf5-rhel9
    not affected: vulnerable code not present
  • Red Hat OpenShift Serverless openshift-serverless-1/kn-eventing-integrations-log-sink-rhel9, openshift-serverless-1/kn-eventing-integrations-aws-s3-sink-rhel9, openshift-serverless-1/kn-eventing-integrations-aws-sns-sink-rhel9, openshift-serverless-1/kn-eventing-integrations-aws-sqs-sink-rhel9, openshift-serverless-1/kn-eventing-integrations-timer-source-rhel9, openshift-serverless-1/kn-eventing-integrations-aws-s3-source-rhel9, +2 more
    not affected: component not present
  • Red Hat 3scale API Management Platform 2 3scale-amp21/system, 3scale-amp22/system, 3scale-amp2/system-rhel7, 3scale-amp2/system-rhel8, 3scale-amp2/system-rhel9
    not affected: vulnerable code not in execute path
  • Red Hat Advanced Cluster Management for Kubernetes 2 rhacm2/console-rhel9 Red Hat AMQ Broker 7 amq-broker-bin.zip, amq-broker-maven-repository.zip Red Hat Ansible Automation Platform 2 automation-gateway, automation-platform-ui, ansible-automation-platform-26/gateway-rhel9, ansible-automation-platform-27/gateway-rhel9, ansible-automation-platform-24/lightspeed-rhel8, ansible-automation-platform-25/lightspeed-rhel8, +3 more Red Hat build of Apache Camel - HawtIO 4 fast-uri Red Hat Build of Podman Desktop rh-podman-desktop.git Red Hat Data Grid 8 redhat-datagrid-maven-repository.zip
    +1 more products
    Red Hat Developer Hub 1 rhdh/rhdh-hub-rhel9, rhdh/red-hat-developer-hub-backstage-plugin-lightspeed, rhdh/red-hat-developer-hub-backstage-plugin-orchestrator, rhdh/red-hat-developer-hub-backstage-plugin-lightspeed-backend, rhdh/red-hat-developer-hub-backstage-plugin-orchestrator-backend, rhdh/red-hat-developer-hub-backstage-plugin-orchestrator-form-widgets, +2 more
    not affected: vulnerable code not present
  • Red Hat Directory Server 11 389-ds-base 1.4.3.34-18.module+el8dsrv+24812+0acb1821 Red Hat Directory Server 12 389-ds-base 2.2.7-18.module+el9dsrv+24814+6d9b6eb5
    not affected: component not present

17 more not affected in the full advisory

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
yes
Technical impact
partial
Assessed
3 mo ago

Exploit prediction

0.38% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Affected packages

ecosystem package affected fixed in
npm fast-uri
<2.4.4
>=3.0.0, <3.1.5
>=4.0.0, <4.1.2
2.4.4
3.1.5
4.1.2

Affected products

  • fast-uri fast-uri

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.