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Fencer Vulns
critical 9.1

CVE-2026-118264 json

Echo: Rejected WebSocket upgrades can bypass Echo route-level access controls

published 2026-10-23 16 d ago modified 2026-11-05 3 d ago also GHSA-cxf3-9h37-7rr8 , GO-2026-6839 , EUVD-2026-112396

cvss
9.1
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 37%
public exploits
0
none known

Summary

Echo is a Go web framework. From 4.0.0 until 4.16.1 and 5.4.1, Echo's Proxy middleware selects a raw tunnel from a client WebSocket upgrade request before verifying that the configured upstream accepted the upgrade. If the upstream rejects the upgrade with an ordinary keep-alive response, later HTTP requests on the connection are sent directly to that upstream without passing through Echo's router or route-specific middleware. This can bypass authentication or authorization enforced only by Echo routes, but requires an accessible proxy route, a cooperating rejected-upgrade response, and a target without independent upstream authorization. This issue is fixed in 4.16.1 and 5.4.1.

Patch / fix

  • go github.com/labstack/echo/v4 4.16.1
  • go github.com/labstack/echo/v5 5.4.1

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-2026-118264 updated cvss 7.4

github.com/labstack/echo: Echo: Rejected WebSocket upgrades can bypass Echo route-level access controls

  • Red Hat Ansible Automation Orchestrator 2026 ansible-automation-platform/automation-orchestrator-temporal-rhel9 Red Hat Cost Management On Premise costmanagement/costmanagement-ros-ocp-backend-rhel9 Red Hat Multicluster Global Hub multicluster-globalhub/multicluster-globalhub-grafana-rhel9 Red Hat Multicluster Global Hub 5 multicluster-globalhub/multicluster-globalhub-grafana-rhel9 Red Hat Advanced Cluster Management for Kubernetes 2 rhacm2/acm-grafana-rhel9, rhacm2/acm-multicluster-observability-addon-rhel9
    affected: workaround, no fix available
  • Red Hat Ceph Storage 5 rhceph/rhceph-5-dashboard-rhel8
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Enterprise Linux 8 grafana, grafana-loki, grafana-mssql, grafana-mysql, grafana-selinux, grafana-graphite, +12 more Red Hat Enterprise Linux 9 grafana, grafana-selinux, osbuild-composer, osbuild-composer-core, osbuild-composer-worker, osbuild-composer-dnf-json Red Hat Enterprise Linux 10 grafana, osbuild-composer Red Hat OpenShift Virtualization 4 container-native-virtualization/hyperconverged-cluster-webhook-rhel9, container-native-virtualization/hyperconverged-cluster-operator-rhel9 Red Hat OpenShift Virtualization 5 container-native-virtualization/hyperconverged-cluster-operator-rhel9
    affected: workaround, no fix available

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
total
Assessed
9 d ago

Exploit prediction

0.43% chance of exploitation in the next 30 days, higher than 37% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 9.1 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
CNA 4.0 9.1 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/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
go github.com/labstack/echo/v4
>=4.0.0, <4.16.1
4.16.1
go github.com/labstack/echo/v5
>=5.0.0, <5.4.1
5.4.1

Affected products

  • labstack echo

Classification

Weakness
  • CWE-444 Inconsistent Interpretation of HTTP Requests
  • CWE-863 Incorrect Authorization

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.