# CVE-2026-54427: Apache bRPC: Stack Exhaustion via Unbounded Recursion in AMF Parser


- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 21 Oct 2026
- **Updated:** 21 Oct 2026
- **Also known as:** GHSA-73m6-hpcv-jggj

## What is CVE-2026-54427?

CVE-2026-54427 is a vulnerability in Apache bRPC, published on 21 Oct 2026. 

### Official description

Uncontrolled recursion in the AMF parser in Apache bRPC < 1.18.0 allows a remote RTMP peer to crash a bRPC process by sending deeply nested AMF objects or arrays. The parser recursively processed nested AMF containers without enforcing a depth limit, which could exhaust the native stack.

Affected Scenarios:
Applications using bRPC RTMP support and parsing AMF data from an untrusted RTMP peer. This includes RTMP servers parsing client command messages, RTMP clients parsing server responses or status messages, and either side parsing inbound AMF script data such as metadata or cue points. Direct callers of ReadAMFObject or ReadAMFArray on untrusted input are also affected.

How to Fix:
1. Upgrade Apache bRPC to 1.18.0.
2. Apply the patch from PR  https://github.com/apache/brpc/pull/3344 .

Note:
The fix introduces a configurable AMF nesting depth limit with default value 128. AMF objects or arrays deeper than amf_max_depth are rejected after applying the fix.

Weakness: CWE-674 (Uncontrolled Recursion)

## Which versions are affected by CVE-2026-54427?


## How do I fix CVE-2026-54427?

No fix has been published for CVE-2026-54427 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-54427 being exploited?

There is no known exploitation of CVE-2026-54427 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-54427 and fix it if it is affected.

What it is: CVE-2026-54427 is a vulnerability in Apache bRPC, published on 21 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-54427 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-2026-54427/ (Markdown: https://insights.sbomify.com/CVE-2026-54427/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-54427
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-54427
- OSV: https://osv.dev/vulnerability/CVE-2026-54427

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-54427/
Summaries are generated and may contain mistakes; the official description above is the record.