CVE-2025-54588
highpriority · track · 0EPSS 0.005 · 41 %ileDEEUUSEPSS · scored 2026-10-26
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.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.9–7.5
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (11)
Products and version ranges known to be affected.
advisories (4)
Vendor and ecosystem advisories describing this.
- WID-SEC-W-2025-1945Google Cloud Platform (Service Mesh): Schwachstelle ermöglicht Denial of ServiceDeutsch2025-09-02csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann eine Schwachstelle in Google Cloud Platform ausnutzen, um einen Denial of Service Angriff durchzuführen.
- WID-SEC-W-2025-2085Red Hat OpenShift Service Mesh: Mehrere SchwachstellenDeutsch2025-09-17csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Red Hat OpenShift Service Mesh ausnutzen, um einen Denial of Service Angriff durchzuführen oder Userrechte zu erlangen.
- GHSA-g9vw-6pvx-7gmwEnvoy: Race condition in Dynamic Forward Proxy leads to use-after-free and segmentation faults2025-09-15ghsa · osvUS
### Summary A use-after-free (UAF) vulnerability in Envoy's DNS cache causes abnormal process termination. Envoy may reallocate memory when processing a pending DNS resolution, causing list iterator to reference freed memory. ### Details The vulnerability exists in Envoy's Dynamic Forward Proxy implementation starting from version v1.34.0. The issue occurs when a completion callback for a DNS resolution triggers new DNS resolutions or removes existing pending resolutions. This condition may occur in the following configuration: 1. Dynamic Forwarding Filter is enabled. 2. `envoy.reloadable_features.dfp_cluster_resolves_hosts` runtime flag is enabled. 3. The Host header is modified between the Dynamic Forwarding Filter and Router filters. ### Impact Denial of service due to abnormal process termination. ### Attack vector(s) Request to Envoy configured as indicated above. ### Patches Users should upgrade to v1.35.1 or v1.34.5. ### Workaround Set the `envoy.reloadable_features.dfp_cluster_resolves_hosts` runtime flag to `false`. ### Detection Abnormal process termination with the `Envoy::Event::DispatcherImpl::runPostCallbacks()` frame in the call stack. ### Credits Rohit Agrawal ([agrawroh](https://github.com/agrawroh)) ([rohit.agrawal@databricks.com](mailto:rohit.agrawal@databricks.com))
- BIT-envoy-2025-54588Envoy: Race condition in Dynamic Forward Proxy leads to use-after-free and segmentation faults2025-09-04vendor · osvUS
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.
also known as (5)
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sources
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references (10)
External citations — patches, advisories, analysis.
- https://github.com/envoyproxy/envoy/releases/tag/v1.34.5cnnvd
- https://github.com/envoyproxy/envoy/releases/tag/v1.35.1cnnvd
- https://github.com/envoyproxy/envoy/security/advisories/GHSA-g9vw-6pvx-7gmwcnnvd
- https://www.envoyproxy.io/Patchcnnvd
- https://github.com/envoyproxy/envoy/releases/tag/v1.34.5enisa_euvd
- https://github.com/envoyproxy/envoy/releases/tag/v1.35.1enisa_euvd
- https://github.com/envoyproxy/envoy/security/advisories/GHSA-g9vw-6pvx-7gmwenisa_euvd
- https://github.com/envoyproxy/envoy/releases/tag/v1.34.5Release Notesnvd
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