{"id":"CVE-2025-54588","aliases":["BIT-envoy-2025-54588","GHSA-g9vw-6pvx-7gmw"],"url":"https://o3.security/vulnerability/CVE-2025-54588","summary":"Envoy: Race condition in Dynamic Forward Proxy leads to use-after-free and segmentation faults","details":"### Summary\n\nA 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.\n\n### Details\n\nThe 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:\n\n1. Dynamic Forwarding Filter is enabled.\n2. `envoy.reloadable_features.dfp_cluster_resolves_hosts` runtime flag is enabled.\n3. The Host header is modified between the Dynamic Forwarding Filter and Router filters.\n\n### Impact\n\nDenial of service due to abnormal process termination.\n\n### Attack vector(s)\nRequest to Envoy configured as indicated above.\n\n### Patches\nUsers should upgrade to v1.35.1 or v1.34.5. \n\n### Workaround\nSet the `envoy.reloadable_features.dfp_cluster_resolves_hosts` runtime flag to `false`.\n\n### Detection\nAbnormal process termination with the `Envoy::Event::DispatcherImpl::runPostCallbacks()` frame in the call stack.\n\n### Credits\nRohit Agrawal ([agrawroh](https://github.com/agrawroh)) ([rohit.agrawal@databricks.com](mailto:rohit.agrawal@databricks.com))","published":"2025-09-02T23:39:07.429Z","modified":"2026-08-12T03:51:43.223549326Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/envoyproxy/envoy","fixedVersion":"1.35.1"},{"ecosystem":"Go","name":"github.com/envoyproxy/envoy","fixedVersion":"1.34.5"}],"fix":null,"references":[{"type":"WEB","url":"https://github.com/envoyproxy/envoy/releases/tag/v1.34.5"},{"type":"WEB","url":"https://github.com/envoyproxy/envoy/releases/tag/v1.35.1"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/54xxx/CVE-2025-54588.json"},{"type":"ADVISORY","url":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-g9vw-6pvx-7gmw"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-54588"},{"type":"PACKAGE","url":"https://github.com/envoyproxy/envoy"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:43.223549326Z"}}