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TI-2025-34359 Aliases CVE-2025-54588GHSA-g9vw-6pvx-7gmw

Envoy: Race condition in Dynamic Forward Proxy leads to use-after-free and segmentation faults

Priority LOW 39CWE-416Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-416 and the CVSS impact.

Summary

Envoy is an open source L7 proxy and communication bus designed for large modern service oriented architectures. Versions 1.34.0 through 1.34.4 and 1.35.0 contain a use-after-free (UAF) vulnerability in the DNS cache, causing abnormal process termination. The vulnerability is in Envoy's Dynamic Forward Proxy implementation, occurring when a completion callback for a DNS resolution triggers new DNS resolutions or removes existing pending resolutions. This condition may occur when the following conditions are met: dynamic Forwarding Filter is enabled, the `envoy.reloadable_features.dfp_cluster_resolves_hosts` runtime flag is enabled, and the Host header is modified between the Dynamic Forwarding Filter and Router filters. This issue is resolved in versions 1.34.5 and 1.35.1. To work around this issue, set the envoy.reloadable_features.dfp_cluster_resolves_hosts runtime flag to false.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00495 42nd percentileScored 2026-11-07
Fix Fixed envoy (envoyproxy): 1.34.5, 1.35.1github.com/envoyproxy/envoy (Go): 1.35.1, 1.34.5Red Hat: 2 advisories

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
envoyproxyenvoy1.34.0 to before 1.34.5; 1.35.0 to before 1.35.11.34.5, 1.35.1Patch availableCNA
—github.com/envoyproxy/envoy (Go)1.35.0 to before 1.35.11.35.1Patch availableGHSA-g9vw-6pvx-7gmw
—github.com/envoyproxy/envoy (Go)1.34.0 to before 1.34.51.34.5Patch availableGHSA-g9vw-6pvx-7gmw
  • envoy Vendorenvoyproxy Affected 1.34.0 to before 1.34.5; 1.35.0 to before 1.35.1 Fixed in 1.34.5, 1.35.1 Patch available CNA
  • github.com/envoyproxy/envoy (Go) Vendor— Affected 1.35.0 to before 1.35.1 Fixed in 1.35.1 Patch available GHSA-g9vw-6pvx-7gmw
  • github.com/envoyproxy/envoy (Go) Vendor— Affected 1.34.0 to before 1.34.5 Fixed in 1.34.5 Patch available GHSA-g9vw-6pvx-7gmw

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*1.34.0 to before 1.34.5Vulnerableenvoyproxy
cpe:2.3:a:envoyproxy:envoy:1.35.0:*:*:*:*:*:*:*1.35.0Vulnerableenvoyproxy
  • cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:* Versions 1.34.0 to before 1.34.5 Vulnerable ·envoyproxy
  • cpe:2.3:a:envoyproxy:envoy:1.35.0:*:*:*:*:*:*:* Versions 1.35.0 Vulnerable ·envoyproxy

Remediation

  • Fix · CNA envoy (envoyproxy) Fixed in 1.34.5, 1.35.1
  • Fix · GHSA-g9vw-6pvx-7gmw github.com/envoyproxy/envoy (Go) Fixed in 1.35.1 Advisory →
  • Fix · GHSA-g9vw-6pvx-7gmw github.com/envoyproxy/envoy (Go) Fixed in 1.34.5 Advisory →

Red Hat 2 advisories

  • RHSA-2025:16044 Released 2025-09-17 · Red Hat rating Important
    Red Hat OpenShift Service Mesh 3.1.2
    • Red Hat OpenShift Service Mesh 3.1 registry.redhat.io/openshift-service-mesh/istio-proxyv2-rhel9
  • RHSA-2025:16040 Released 2025-09-17 · Red Hat rating Important
    Red Hat OpenShift Service Mesh 3.0.5
    • Red Hat OpenShift Service Mesh 3.0 registry.redhat.io/openshift-service-mesh/istio-proxyv2-rhel9

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat OpenShift Service Mesh 3.0Fixed RHSA-2025:16040
Red Hat OpenShift Service Mesh 3.1Fixed RHSA-2025:16044
Not affected: 3 products
  • OpenShift Service Mesh 3
  • Red Hat OpenShift Service Mesh 3.0
  • Red Hat OpenShift Service Mesh 3.1

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-54588
  2. 2026-10-03 Alias added: GHSA-g9vw-6pvx-7gmw

References

Patch 1

Advisory 1

Other 3

  • TI-2026-79288 Out-of-bounds write in Google Brotli decoder KEVCVSS 4.0CRITICAL 9.2
  • TI-2023-23979 The HTTP/2 protocol allows a denial of service (server resource consumption) because… KEVCVSS 3.1HIGH 7.5
  • TI-2024-20001 HTTP/2: CPU exhaustion due to CONTINUATION frame flood CVSS 3.1HIGH 7.5
  • TI-2024-18524 HTTP/2: memory exhaustion due to CONTINUATION frame flood CVSS 3.1HIGH 7.5
  • TI-2023-12215 Envoy client may fake the header `x-envoy-original-path` CVSS 3.1CRITICAL 9.1
  • TI-2023-18002 Envoy vulnerable to OAuth2 credentials exploit with permanent validity CVSS 3.1CRITICAL 9.8
See all 126 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences