CVE-2026-47205Public exploitNetwork attack vector

Proxy crash via ext_authz client use-after-free

Published Jun 26, 2026 · Updated Jun 26, 2026

Use-after-free in Envoy's ext_authz HTTP filter allows remote attackers to crash the proxy through rapid downstream disconnects. The filter moves a transient per-route authorization client into client_, destroying the default client while an asynchronous authorization check remains in flight. A target route must use an HTTP or gRPC per-route service override, and a disconnect during the check allows a late callback to dereference destroyed stream state and terminate a data-plane worker.

CVSS severity5.9
Medium
EPSS probability0.39%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Envoy's ext_authz HTTP filter allows remote attackers to crash the proxy through rapid downstream disconnects. The filter moves a transient per-route authorization client into client_, destroying the default client while an asynchronous authorization check remains in flight. A target route must use an HTTP or gRPC per-route service override, and a disconnect during the check allows a late callback to dereference destroyed stream state and terminate a data-plane worker.

The record

CVE
CVE-2026-47205
Published
Jun 26, 2026
Updated
Jun 26, 2026
Vendor
Envoy Proxy
Product
Envoy
Classifications
CWE-416, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 26, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 1.36.0, < 1.36.9
  2. Affected versionversion=>= 1.37.0, < 1.37.5
  3. Affected versionversion=>= 1.38.0, < 1.38.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Envoy Proxy · Envoyversion=>= 1.36.0, < 1.36.9; version=>= 1.37.0, < 1.37.5; version=>= 1.38.0, < 1.38.3

Published CVSS scores

5.9GitHub CNACVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-416Use After Free
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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