# CVE-2026-78066: Apache bRPC resource exhaustion in compression and wire parsers

Source: https://junglewise.ai/threats/cve-2026-78066-resource-exhaustion-in-apache-brpc-version-1-18-0-on-all  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-21. Updated: 2026-10-21  
License: CC BY 4.0 with a link back

CVE-2026-78066 · Severity: info · Published 2026-10-21

Apache bRPC is a high-performance RPC framework used in microservices communication. Multiple parsers in versions before 1.18.0 fail to enforce size limits on decompressed data and wire-declared message lengths, allowing an attacker to send specially crafted requests that consume excessive memory and crash the service.

Technologies: [Apache Brpc](https://junglewise.ai/threats/technologies/brpc). Vendors: [Apache](https://junglewise.ai/threats/vendors/apache).

## Quick answers

**Is CVE-2026-78066 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-78066 being exploited in the wild.

**How severe is CVE-2026-78066?** Informational severity, published 21 October 2026.

**Which products and versions are affected?** Apache Brpc < 1.18.0.

**Is there a fix for CVE-2026-78066?** Yes: fixed in bRPC 1.18.0. Until then: Restrict network access to bRPC services accepting gzip/zlib/snappy compression or rtmp, sofa-pbrpc, and mcpack2pb protocols from untrusted clients until patching is possible. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-78066 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-78066?** Check whether you run Apache Brpc at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in bRPC 1.18.0

Restrict network access to bRPC services accepting gzip/zlib/snappy compression or rtmp, sofa-pbrpc, and mcpack2pb protocols from untrusted clients until patching is possible.

## Technical details

The vulnerability spans multiple attack vectors: gzip/zlib/snappy decompressors check size limits only against compressed bytes (allowing GiB-scale decompression from small inputs), AMF string readers pre-allocate based on declared length before bytes arrive, RTMP chunk headers permit mid-stream length re-declaration without bounds, sofa-pbrpc does not bound meta_size, and mcpack2pb trusts wire-declared item counts and underflows on zero value_size. All require attacker control over wire data sent to a bRPC service, and successful exploitation causes memory exhaustion and process termination.

## Affected products

- Apache bRPC < 1.18.0

## Timeline

- 2026-10-21: disclosed

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