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Fencer Vulns
high 7.5

CVE-2026-75899 json

fast-uri vulnerable to server-side request forgery via repeated hostname percent-decoding

published 2026-08-24 2 mo ago modified 2026-10-14 25 d ago also GHSA-fph4-wmhf-6fwf , EUVD-2026-64763

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 12%
public exploits
0
none known

Summary

fast-uri is a URI parser for Node.js. It decodes percent escapes in a hostname during parsing and then decodes the parsed hostname a second time during authority recomposition, so a single call to normalize or resolve can turn nested percent-encoded input into a different network destination such as a loopback hostname or address. For example, a doubly encoded host that spells out a loopback name decodes to that live host in one operation, which contradicts RFC 3986 section 2.4 that an implementation must not decode the same string more than once. An application that normalizes or resolves an untrusted HTTP-family URI before outbound routing, redirect validation, or a host-policy check can receive a destination different from the one the original encoded host represented, giving a server-side request forgery and host-policy bypass primitive. This is an incomplete-fix variant of CVE-2026-6322. The affected versions are 2.4.1 up to but not including 2.4.5, 3.1.2 up to but not including 3.1.6, and 4.0.0 up to but not including 4.1.3. The issue is fixed in 2.4.5, 3.1.6, and 4.1.3, which normalize percent escapes once and preserve encoded percent signs. Users should upgrade to a patched version.

Patch / fix

  • npm fast-uri 2.4.5, 3.1.6, 4.1.3
  • fast-uri fast-uri 2.4.5, 3.1.6, 4.1.3
  • node-ajv Debian 14 8.20.0~ds+~cs7.1.4-1

debian advisories DEBIAN-CVE-2026-75899

  • foreman satellite utils 6.19, satellite capsule 6.19, satellite 6.19 3.18.0.14-1.el9sat
  • foreman-cli satellite utils 6.19, satellite 6.19 3.18.0.14-1.el9sat
  • foreman-ec2 satellite 6.19 3.18.0.14-1.el9sat
  • foreman-pcp satellite capsule 6.19, satellite 6.19 3.18.0.14-1.el9sat
  • foreman-redis satellite 6.19 3.18.0.14-1.el9sat
  • foreman-vmware satellite 6.19 3.18.0.14-1.el9sat
  • foreman-libvirt satellite 6.19 3.18.0.14-1.el9sat
  • foreman-service satellite 6.19 3.18.0.14-1.el9sat

red hat advisories RHSA-2026:74503RHSA-2026:71543RHSA-2026:60866RHSA-2026:60856RHSA-2026:60855

  • agama-web-ui openSUSE Tumbleweed 25+475.275dd4727-56.1

opensuse advisories openSUSE-SU-2026:12424-1

  • cockpit-image-builder AlmaLinux 10 94.4-1.el10_2

almalinux advisories ALSA-2026:71543

  • cockpit-image-builder Rocky Linux 10 94.4-1.el10_2

rocky linux advisories RLSA-2026:71543

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-2026-75899 updated cvss 7.5

fast-uri: fast-uri: Server-Side Request Forgery via repeated hostname percent-decoding

  • 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-rhel9, openshift-pipelines/pipelines-console-plugin-pf5-rhel9 Red Hat OpenShift Serverless openshift-serverless-1/kn-eventing-integrations-transform-jsonata-rhel9
    affected: workaround, no fix available
  • Red Hat Ansible Automation Platform 2 ansible-automation-platform-24/lightspeed-rhel8, ansible-automation-platform-25/lightspeed-rhel8, ansible-automation-platform-26/lightspeed-rhel9
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Build of Podman Desktop rh-podman-desktop.git 1.1.0
    affected: workaround, no fix available
  • Red Hat Data Grid 8 redhat-datagrid-maven-repository.zip 8.6.1.CR1
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Enterprise Linux 10 rh-podman-desktop 1.1.2-1.el10_2
    affected: workaround, no fix planned “Out of support scope”
  • 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-mlflow-rhel9, rhoai/odh-core-bff-rhel9, rhoai/odh-dashboard-operator-rhel9, rhoai/odh-mod-arch-agent-ops-rhel9 Red Hat OpenShift Container Platform 5 openshift5/ose-monitoring-plugin-rhel9, openshift5/nmstate-console-plugin-rhel9 Red Hat Openshift Data Foundation 4 odf4/mcg-core-rhel9, odf4/ocs-client-console-rhel9, rhceph-dev/odf4-mcg-core-rhel9, rhceph-dev/odf4-odf-console-rhel9, odf4/odf-multicluster-console-rhel9, rhceph-dev/odf4-ocs-client-console-rhel9, +1 more Red Hat Satellite 6 nodejs-webpack 5.104.1-1.el9sat, nodejs-mini-css-extract-plugin 2.10.0-1.el9sat, nodejs-compression-webpack-plugin 10.0.0-2.el9sat
    affected: workaround, no fix available
  • Red Hat Secrets Management Console for Red Hat OpenShift external-secrets-management/console-plugin-rhel9
    affected: workaround, no fix available “Fix deferred”
show 27 more
  • Red Hat Cluster Observability Operator 1.5 cluster-observability-operator/distributed-tracing-console-plugin-rhel9 1793661918, cluster-observability-operator/distributed-tracing-console-plugin-rhel9 1793824908, cluster-observability-operator/troubleshooting-panel-console-plugin-rhel9 1790854494, cluster-observability-operator/distributed-tracing-console-plugin-pf4-rhel9 1793661804, cluster-observability-operator/distributed-tracing-console-plugin-pf4-rhel9 1793823428, cluster-observability-operator/distributed-tracing-console-plugin-pf5-rhel9 1793664067, +3 more
    fixed: vendor fix RHSA-2026:95591
  • Red Hat multicluster engine for Kubernetes 2.11 multicluster-engine/console-mce-rhel9 1790133081
    fixed: vendor fix RHSA-2026:72848
  • Red Hat multicluster engine for Kubernetes 2.17 multicluster-engine/console-mce-rhel9 1790135323
    fixed: vendor fix RHSA-2026:72849
  • Red Hat Network Observability (NETOBSERV) 1.12.3 network-observability/network-observability-console-plugin-rhel9 1789978277, network-observability/network-observability-console-plugin-pf5-rhel9 1789978780
    fixed: vendor fix RHSA-2026:70593
  • Red Hat Advanced Cluster Management for Kubernetes 2.16 rhacm2/console-rhel9 1788283612, rhacm2/console-rhel9 1788880980
    fixed: vendor fix RHSA-2026:67542
  • Red Hat Advanced Cluster Management for Kubernetes 2.17 rhacm2/console-rhel9 1788883472
    fixed: vendor fix RHSA-2026:67543
  • Red Hat Ansible Automation Platform 2.1 ansible-automation-platform/automation-portal 1788775748
    fixed: vendor fix RHSA-2026:65118
  • Red Hat Ansible Automation Platform 2.2 ansible-automation-platform/automation-portal 1788783591, ansible-automation-platform/bootc-automation-portal-rhel9 1791865660
    fixed: vendor fix RHSA-2026:65155
  • Red Hat Ansible Automation Platform 2.6 ansible-automation-platform-tech-preview/mcp-server-rhel9 1789669036
    fixed: vendor fix RHSA-2026:71179
  • Red Hat Ansible Automation Platform 2.7 ansible-automation-platform-27/mcp-server-rhel9 1788915736
    fixed: vendor fix RHSA-2026:67279
  • Red Hat Cost Management On-Premise 1 costmanagement/costmanagement-ui-rhel10 1791460851
    fixed: vendor fix RHSA-2026:79357
  • Red Hat Developer Hub 1.9 rhdh/rhdh-hub-rhel9 1789554285
    fixed: vendor fix RHSA-2026:69248
  • Red Hat Developer Hub 1.10 rhdh/rhdh-hub-rhel9 1791311495, rhdh/red-hat-developer-hub-backstage-plugin-orchestrator 1791250003, rhdh/red-hat-developer-hub-backstage-plugin-lightspeed-backend 1791242697, rhdh/red-hat-developer-hub-backstage-plugin-orchestrator-backend 1791251282, rhdh/red-hat-developer-hub-backstage-plugin-orchestrator-form-widgets 1791250794, rhdh/red-hat-developer-hub-backstage-plugin-orchestrator-backend-module-loki 1791250355, +1 more
    fixed: vendor fix RHSA-2026:76788
  • Red Hat Discovery 2 discovery/discovery-ui-rhel9 1788206196
    fixed: vendor fix RHSA-2026:61783
  • Red Hat Edge Manager 1.1 rhem/flightctl-ui-rhel10 1789486181, rhem/flightctl-ui-ocp-rhel9 1789486446, rhem/flightctl-ui-ocp-rhel10 1789486226
    fixed: vendor fix RHSA-2026:68044
  • Red Hat Edge Manager 1.2 rhem/flightctl-ui-rhel9 1789486750, rhem/flightctl-ui-rhel10 1789488111, rhem/flightctl-ui-ocp-rhel9 1789486476, rhem/flightctl-ui-ocp-rhel10 1789485920
    fixed: vendor fix RHSA-2026:68006
  • Red Hat Enterprise Linux AppStream (v. 10) cockpit-image-builder 94.4-1.el10_2
    fixed: vendor fix RHSA-2026:71543
  • Red Hat Hardened Images grafana12.4 12.4.9-0.4.hum1, grafana13.1 13.1.3-0.3.hum1, grafana13.2 13.2.0-0.1.2.hum1
    fixed: vendor fix RHSA-2026:60866
  • Red Hat Migration Toolkit 1.8 rhmtc/openshift-migration-ui-rhel8 1789546373
    fixed: vendor fix RHSA-2026:68681
  • Red Hat OpenShift AI 2.25 rhoai/odh-dashboard-rhel9 1791853525, rhoai/odh-feature-server-rhel9 1792148523, 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
  • Red Hat OpenShift AI 3.5 rhoai/odh-workbench-codeserver-datascience-cpu-py312-rhel9 1791825469
    fixed: vendor fix RHSA-2026:86891
  • 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
    fixed: vendor fix RHSA-2026:68553
  • Red Hat Openshift Data Foundation 4.19 odf4/odf-console-rhel9 1793126829
    fixed: vendor fix RHSA-2026:92650
  • Red Hat OpenShift Dev Spaces 3.30 devspaces/dashboard-rhel9 1789162884
    fixed: vendor fix RHSA-2026:68754
  • Red Hat OpenShift Dev Spaces 3.31 devspaces/code-rhel9 1792599388
    fixed: vendor fix RHSA-2026:90321

3 more fixed, 43 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
2 mo ago

Exploit prediction

0.22% chance of exploitation in the next 30 days, higher than 12% 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
>=2.4.1, <2.4.5
>=3.1.2, <3.1.6
>=4.0.0, <4.1.3
2.4.5
3.1.6
4.1.3

Affected products

  • fast-uri fast-uri

Classification

Weakness
  • CWE-174 Double Decoding of the Same Data
  • CWE-918 Server-Side Request Forgery

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.