CVE-2022-29227: Use after free in Envoy

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2022-06-09 · updated 2026-06-17
Weakness: CWE-416

Description

Envoy is a cloud-native high-performance edge/middle/service proxy. In versions prior to 1.22.1 if Envoy attempts to send an internal redirect of an HTTP request consisting of more than HTTP headers, there’s a lifetime bug which can be triggered. If while replaying the request Envoy sends a local reply when the redirect headers are processed, the downstream state indicates that the downstream stream is not complete. On sending the local reply, Envoy will attempt to reset the upstream stream, but as it is actually complete, and deleted, this result in a use-after-free. Users are advised to upgrade. Users unable to upgrade are advised to disable internal redirects if crashes are observed.

Affected products

envoyproxy envoy: before 1.22.1 — fixed in 1.22.1

How to fix

Upgrade to a fixed version: envoyproxy envoy 1.22.1. Check the vendor advisory for mitigations.

References

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