CVE-2026-26330
Received Received - Intake
Use-After-Free Vulnerability in Envoy Rate Limit Filter Causes Crash

Publication date: 2026-03-10

Last updated on: 2026-03-11

Assigner: GitHub, Inc.

Description
Envoy is a high-performance edge/middle/service proxy. Prior to 1.37.1, 1.36.5, 1.35.8, and 1.34.13, At the rate limit filter, if the response phase limit with apply_on_stream_done in the rate limit configuration is enabled and the response phase limit request fails directly, it may crash Envoy. When both the request phase limit and response phase limit are enabled, the safe gRPC client instance will be re-used for both the request phase request and response phase request. But after the request phase request is done, the inner state of the request phase limit request in gRPC client is not cleaned up. When a second limit request is sent at response phase, and the second limit request fails directly, the previous request's inner state may be accessed and result in crash. This vulnerability is fixed in 1.37.1, 1.36.5, 1.35.8, and 1.34.13.
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Meta Information
Published
2026-03-10
Last Modified
2026-03-11
Generated
2026-06-16
AI Q&A
2026-03-10
EPSS Evaluated
2026-06-14
NVD
EUVD
Affected Vendors & Products
Showing 4 associated CPEs
Vendor Product Version / Range
envoyproxy envoy to 1.34.13 (exc)
envoyproxy envoy From 1.35.0 (inc) to 1.35.8 (exc)
envoyproxy envoy From 1.36.0 (inc) to 1.36.5 (exc)
envoyproxy envoy 1.37.0
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-416 The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
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Executive Summary

This vulnerability affects Envoy, a high-performance proxy. It occurs in the rate limit filter when both request phase and response phase limits are enabled with the apply_on_stream_done setting. If the response phase limit request fails directly, Envoy may crash because the internal state from the previous request phase limit request is not properly cleaned up before the response phase request is processed.

Impact Analysis

The vulnerability can cause Envoy to crash when certain rate limit requests fail during the response phase. This crash can lead to denial of service, disrupting the availability of services relying on Envoy as a proxy.

Compliance Impact

I don't know

Detection Guidance

I don't know

Mitigation Strategies

To mitigate this vulnerability, upgrade Envoy to one of the fixed versions: 1.37.1, 1.36.5, 1.35.8, or 1.34.13.

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