What’s Vulnerable › Vulnerabilities

CVE-2026-84304: gRPC-Go: Heap Memory Exhaustion (OOM) via HTTP/2 DATA Frame Fragmentation

• Severity: high (CVSS 8.7 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-01 · updated 2026-09-09
• Weakness: CWE-400

Description

gRPC-Go is the Go language implementation of gRPC. Prior to 1.83.1, internal/transport/transport.go stores each fragmented HTTP/2 DATA frame as a separate recvMsg in recvBuffer, so millions of one-byte frames can consume disproportionate heap memory even when payload bytes remain within connection and stream flow-control windows. An unauthenticated remote attacker can use concurrent multiplexed streams to exhaust process memory and cause a runtime panic or out-of-memory termination. Receive-buffer compaction is enabled by default and can be controlled temporarily with GRPC_GO_EXPERIMENTAL_ENABLE_RECEIVE_BUFFER_COMPACTION. This issue is fixed in version 1.83.1.

Affected products

• Google.Golang.Org/Grpc: before 1.83.1 — fixed in 1.83.1
• Google gRPC: before 1.83.1

How to fix

Upgrade to a fixed version: Google.Golang.Org/Grpc 1.83.1. Check the vendor advisory for mitigations.

References

• https://github.com/grpc/grpc-go/commit/7354d9c8debb4bcf2225bf429857078de310c176
• https://github.com/grpc/grpc-go/commit/8cfeca0e1ee5ea0980dcc320e20240fa1079ec77
• https://github.com/grpc/grpc-go/pull/9331
• https://github.com/grpc/grpc-go/pull/9333
• https://github.com/grpc/grpc-go/releases/tag/v1.83.1
• https://github.com/grpc/grpc-go/security/advisories/GHSA-vp52-pcj8-j9qc

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