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6.5 Medium

CVE-2025-62504 Envoy is an open source edge and service proxy

Description

Envoy is an open source edge and service proxy. Envoy versions earlier than 1.36.2, 1.35.6, 1.34.10, and 1.33.12 contain a use-after-free vulnerability in the Lua filter. When a Lua script executing in the response phase rewrites a response body so that its size exceeds the configured per_connection_buffer_limit_bytes (default 1MB), Envoy generates a local reply whose headers override the original response headers, leaving dangling references and causing a crash. This results in denial of service. Updating to versions 1.36.2, 1.35.6, 1.34.10, or 1.33.12 fixes the issue. Increasing per_connection_buffer_limit_bytes (and for HTTP/2 the initial_stream_window_size) or increasing per_request_buffer_limit_bytes / request_body_buffer_limit can reduce the likelihood of triggering the condition but does not correct the underlying memory safety flaw.

Affected products and versions

Product Affected versions Fixed in
envoy 1.350 1.350 → 1.35.5 No fix stated
envoy 1.36 1.36.0 → 1.36.1 No fix stated
envoy 1.34 1.34.0 → 1.34.9 No fix stated
envoy 1.33 earliest → 1.33.11 No fix stated

References

Timeline

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