CVE-2025-54588
Envoy: Race condition in Dynamic Forward Proxy leads to use-after-free and segmentation faults
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
Description
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVDNVD · Analyzed | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.50% · top 57% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Weakness
Affected products
- affected >= 1.34.0, < 1.34.5
- affected >= 1.35.0, < 1.35.1
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Gogithub.com/envoyproxy/envoyGHSA-g9vw-6pvx-7gmw (opens in a new tab)
References (3)
- https://github.com/envoyproxy/envoy/security/advisories/GHSA-g9vw-6pvx-7gmw (opens in a new tab)x_refsource_CONFIRM
- https://github.com/envoyproxy/envoy/releases/tag/v1.34.5 (opens in a new tab)x_refsource_MISC
- https://github.com/envoyproxy/envoy/releases/tag/v1.35.1 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-g9vw-6pvx-7gmw (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2025-54588)Record last updated .