# CVE-2026-54425: Apache bRPC: Stack Exhaustion via Recursive HPACK Dynamic Table Size Update Decoding


- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 21 Oct 2026
- **Updated:** 21 Oct 2026
- **Also known as:** GHSA-95vv-8ch6-6f8f

## What is CVE-2026-54425?

CVE-2026-54425 is a vulnerability in Apache bRPC, published on 21 Oct 2026. 

### Official description

Uncontrolled recursion in the HTTP/2 HPACK decoder in Apache bRPC before 1.18.0 allows remote attackers to cause denial of service by sending a crafted HTTP/2 header block containing many consecutive Dynamic Table Size Update entries. Each update was decoded by recursively invoking the HPACK decoder, which could exhaust the thread stack before a header field or end of input was reached.

Root Cause:
The bRPC HPACK decoder recursively decoded the next entry after processing a Dynamic Table Size Update. The decoder did not bound the recursion depth, so a long sequence of update entries could consume excessive stack space.

Affected Scenarios:
Use bRPC with the built-in HTTP/2 implementation to accept HTTP/2 traffic from an 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/3343 

Note:
The fix changes HPACK Dynamic Table Size Update decoding to use iterative parsing instead of recursive parsing.

Weakness: CWE-674 (Uncontrolled Recursion)

## Which versions are affected by CVE-2026-54425?


## How do I fix CVE-2026-54425?

No fix has been published for CVE-2026-54425 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-54425 being exploited?

There is no known exploitation of CVE-2026-54425 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-54425 and fix it if it is affected.

What it is: CVE-2026-54425 is a vulnerability in Apache bRPC, published on 21 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-54425 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-2026-54425/ (Markdown: https://insights.sbomify.com/CVE-2026-54425/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-54425
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-54425
- OSV: https://osv.dev/vulnerability/CVE-2026-54425

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-54425/
Summaries are generated and may contain mistakes; the official description above is the record.