# CVE-2026-74758: Apache bRPC: Heap Use-After-Free in RTMP Abort Message Handling


- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 21 Oct 2026
- **Updated:** 21 Oct 2026
- **Also known as:** GHSA-jhf7-xcw3-gmv5

## What is CVE-2026-74758?

CVE-2026-74758 is a vulnerability in Apache bRPC, published on 21 Oct 2026. 

### Official description

A heap use-after-free in the RTMP protocol component of Apache bRPC (versions < 1.18.0) allows a remote attacker to crash a bRPC RTMP server by sending a crafted Abort control message. No authentication or application-level request is required.

Root Cause:
When an RTMP Abort control message names the chunk stream that is currently being parsed (the chunk stream carrying the message itself), RtmpChunkStream::OnAbortMessage calls RtmpContext::ClearChunkStream, which deletes the RtmpChunkStream while its Feed() is still running. After the message handler returns, Feed() continues to access members of the deleted object, resulting in a heap-use-after-free.

Affected Scenarios:
bRPC servers that enable RTMP support (ServerOptions.rtmp_service set) and accept connections from untrusted networks.

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/3452 

The fix skips clearing the chunk stream when the Abort message targets the chunk stream that is currently being parsed.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2026-74758?


## How do I fix CVE-2026-74758?

No fix has been published for CVE-2026-74758 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-74758 being exploited?

There is no known exploitation of CVE-2026-74758 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74758 and fix it if it is affected.

What it is: CVE-2026-74758 is a vulnerability in Apache bRPC, published on 21 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-74758 in the wild and no public exploit code.

Affected product: Apache bRPC. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-74758/ (Markdown: https://insights.sbomify.com/CVE-2026-74758/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74758
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74758
- OSV: https://osv.dev/vulnerability/CVE-2026-74758

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74758/
Summaries are generated and may contain mistakes; the official description above is the record.