CVE-2026-26330 Envoy's global rate limit may crash when the response phase limit is enabled and the response phase request is failed directly
Attackers can crash Envoy proxy by triggering a use-after-free in the rate limit filter when response phase limits are enabled and fail.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-26330?
CVE-2026-26330 is a medium-severity use after free vulnerability in Envoyproxy Envoy, published on 10 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Weakness: CWE-416
Which versions are affected by CVE-2026-26330?
5 open source packages ship an affected version, including github.com/envoyproxy/envoy and envoy. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/envoyproxy/envoy Go | All versions | None |
github.com/envoyproxy/envoy Go | All versions | None |
github.com/envoyproxy/envoy Go | From 1.36.0 to 1.36.4 | None |
github.com/envoyproxy/envoy Go | From 1.36.0 to 1.36.4 | None |
envoy Bitnami | All versions | 1.34.13, 1.35.9, 1.36.5, 1.37.1 |
Products include Envoyproxy Envoy.
How do I fix CVE-2026-26330?
Upgrade to a fixed version.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-26330 being exploited?
There is no known exploitation of CVE-2026-26330 in the wild and no public exploit code.
Other vulnerabilities in Envoyproxy Envoy
Sources
Also known as BIT-envoy-2026-26330, GHSA-c23c-rp3m-vpg3.