CVE-2025-54588
published 2025-09-03CVE-2025-54588: 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…
PriorityP340high7.5CVSS 3.1
AVNACLPRNUINSUCNINAH
EPSS
0.44%
35.1th percentile
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.
Affected
6 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| envoyproxy | envoy | — | — |
| envoyproxy | envoy | — | — |
| envoyproxy | envoy | — | — |
| envoyproxy | envoy | >= 1.34.0 < 1.34.5 | 1.34.5 |
| github.com | envoyproxy_envoy | >= 1.34.0 < 1.34.5 | 1.34.5 |
| github.com | envoyproxy_envoy | >= 1.35.0 < 1.35.1 | 1.35.1 |
CVSS provenance
nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
vendor_redhat7.5HIGH
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GHSA
Envoy: Race condition in Dynamic Forward Proxy leads to use-after-free and segmentation faults
ghsa·2025-09-15
CVE-2025-54588 [HIGH] CWE-416 Envoy: Race condition in Dynamic Forward Proxy leads to use-after-free and segmentation faults
Envoy: Race condition in Dynamic Forward Proxy leads to use-after-free and segmentation faults
### 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
OSV
Envoy: Race condition in Dynamic Forward Proxy leads to use-after-free and segmentation faults
osv·2025-09-15
CVE-2025-54588 [HIGH] Envoy: Race condition in Dynamic Forward Proxy leads to use-after-free and segmentation faults
Envoy: Race condition in Dynamic Forward Proxy leads to use-after-free and segmentation faults
### 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
Red Hat
envoyproxy/envoy: Use after free in DNS cache
vendor_redhat·2025-09-03·CVSS 7.5
CVE-2025-54588 [HIGH] CWE-416 envoyproxy/envoy: Use after free in DNS cache
envoyproxy/envoy: Use after free in DNS cache
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
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
2025-09-03
Published