Is CVE-2026-73547 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-73547 being exploited in the wild.

How severe is CVE-2026-73547?

High severity, with a CVSS score of 7.5, published 21 September 2026.

Which products and versions are affected?

Envoy before 1.36.10, before 1.37.6, before 1.38.4, before 1.39.1.

Is there a fix for CVE-2026-73547?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-73547 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-73547?

Check whether you run Envoy at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-73547: Envoy null pointer dereference in ext_authz filter

CVE-2026-73547 · Severity: high · CVSS 7.5 · Published 2026-09-21

Envoy is an open source proxy used in cloud-native applications to route and filter traffic. The ext_authz filter, which applies authorization policies using query parameters, crashes when processing path-less CONNECT requests if query parameter mutation is configured. An unauthenticated attacker can trigger this crash to cause a denial of service by disrupting traffic through the proxy.

Technologies: Envoy. Vendors: Envoy.

Quick answers

Is CVE-2026-73547 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-73547 being exploited in the wild.
How severe is CVE-2026-73547?: High severity, with a CVSS score of 7.5, published 21 September 2026.
Which products and versions are affected?: Envoy before 1.36.10, before 1.37.6, before 1.38.4, before 1.39.1.
Is there a fix for CVE-2026-73547?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-73547 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-73547?: Check whether you run Envoy at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The ext_authz filter assumes request_headers_->Path() returns a non-null value when applying query_parameters_to_set or query_parameters_to_remove mutations. Path-less CONNECT requests return null for the path, causing a null pointer dereference in Filter::onComplete during query string parsing. The vulnerability requires the deployment to accept path-less CONNECT requests and configure ext_authz with query-parameter mutation; an unauthenticated downstream client can trigger the crash over the network.

Affected products

Envoy Envoy before 1.36.10, before 1.37.6, before 1.38.4, before 1.39.1

Timeline

2026-09-21: disclosed

References

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