CVE-2026-73547 Envoy ext_authz: request `:path` pseudoheader dereferenced w/o null check
An unauthenticated attacker can crash the Envoy proxy by sending a path-less CONNECT request when ext_authz query-parameter mutation is configured.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-73547?
CVE-2026-73547 is a high-severity vulnerability in Envoyproxy Envoy, published on 21 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.36.10, 1.37.6, 1.38.4, and 1.39.1, Envoy's ext_authz filter assumes that a request contains a :path pseudoheader when applying query_parameters_to_set or query_parameters_to_remove from an authorization response. A path-less CONNECT request makes request_headers_->Path() return null, and Filter::onComplete dereferences that pointer while parsing the query string. An unauthenticated downstream client can crash the Envoy process when the filter and authorization response use query-parameter mutation. The relevant scope boundary is that the deployment must accept path-less CONNECT and configure ext_authz query-parameter mutation. This issue is fixed in versions 1.36.10, 1.37.6, 1.38.4, and 1.39.1.
Which versions are affected by CVE-2026-73547?
1 open source package ship an affected version, including envoy. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
envoy Bitnami | All versions | 1.36.10, 1.37.6, 1.38.4, 1.39.1 |
Products include Envoyproxy Envoy.
How do I fix CVE-2026-73547?
Upgrade envoy to a fixed version for your release line: 1.36.10, 1.37.6, 1.38.4 or 1.39.1.
Is CVE-2026-73547 being exploited?
There is no known exploitation of CVE-2026-73547 in the wild and no public exploit code.
Other vulnerabilities in Envoyproxy Envoy
Sources
Also known as BIT-envoy-2026-73547, GHSA-87ph-jqwm-pg6r, MINI-444v-2hmv-7rvm, MINI-cp2r-m2gm-cjx6, MINI-f4r5-8mv9-wrwp, MINI-hvc9-x86w-85fr.