CVE-2023-32731: Grpc

High severity, CVSS 7.5. EPSS: 0.5% chance of exploitation in the next 30 days.

When gRPC HTTP2 stack raised a header size exceeded error, it skipped parsing the rest of the HPACK frame. This caused any HPACK table mutations to also be skipped, resulting in a desynchronization of HPACK tables between sender and receiver. If leveraged, say, between a proxy and a backend, this could lead to requests from the proxy being interpreted as containing headers from different proxy clients - leading to an information leak that can be used for privilege escalation or data exfiltration. We recommend upgrading beyond the commit contained in  https://github.com/grpc/grpc/pull/33005 https://github.com/grpc/grpc/pull/33005

Affected products

• Grpc Grpc: from 1.53.0, before 1.55.0 (fixed in 1.55.0)

Published 2023-06-09. Last modified 2026-06-17.