Envoy's global rate limit may crash when the response phase limit is enabled and the response phase request is failed directly

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

5.3 · CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS

• CVE-2026-26330: 0.33% estimated exploitation activity in the next 30 days; percentile 26.88 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary At the rate limit filter, if we enabled the response phase limit with applyonstreamdone in the rate limit configuration and the response phase limit request fails directly, it may crash Envoy. Details 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 we send the second limit request at response phase, and the second limit request fails directly, we may access the previous request's inner state and result in crash. PoC This need to mock the network failure. But we have reproduced by unit test locally. Impact This only happens when both the request phase limit and response phase limit are enabled in the rate limit filter, and requires the request to rate limit service fails directly (For example, if from Envoy's…

Published by the source

10 Mar 2026, 18:31 UTC

Last modified by the source

18 Mar 2026, 13:43 UTC

Source last checked

26 Oct 2026, 15:18 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-c23c-rp3m-vpg3

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# Patch Next advisory brief: CVE-2026-26330

Advisory: Envoy's global rate limit may crash when the response phase limit is enabled and the response phase request is failed directly
IDs: CVE-2026-26330, GHSA-c23c-rp3m-vpg3
Record: https://patchnext.com/advisories/cve-2026-26330 (revision 1, source checked 26 Oct 2026, 15:18 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/envoyproxy/envoy: affected >= 1.37.0, <= 1.37.0; >= 1.36.0, <= 1.36.4

## Suggested inspection (read-only)
- Go github.com/envoyproxy/envoy: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/envoyproxy/envoy.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-c23c-rp3m-vpg3 (GitHub-reviewed advisory GHSA-c23c-rp3m-vpg3 lists affected ranges: Go github.com/envoyproxy/envoy >=1.37.0 =1.36.0 <=1.36.4)

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