# GHSA-2fcv-qww3-9v6h: Babylon's malformed vote extensions are not rejected

> Adversarial validators can halt the blockchain by sending malformed vote extensions, requiring high-privilege access to exploit.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 24 Nov 2025
- **Also known as:** GO-2025-4157

## What is GHSA-2fcv-qww3-9v6h?

GHSA-2fcv-qww3-9v6h is a denial of service vulnerability in github.com/babylonlabs-io/babylon, published on 24 Nov 2025. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

### Summary

Adversarial validators can send large vote extensions by using non-existing protobuf tags. This will result in the rejection of the subsequent block proposal. Eventually, all block proposals will be rejected by all validators.

### Impact

A small group of adversarial validators can cause a chain halt.

## Which versions are affected by GHSA-2fcv-qww3-9v6h?

6 open source packages ship an affected version, including github.com/babylonlabs-io/babylon/v4, github.com/babylonlabs-io/babylon and github.com/babylonlabs-io/babylon/v2.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/babylonlabs-io/babylon/v4` | Go | All versions | 4.1.0 |
| `github.com/babylonlabs-io/babylon/v4` | Go | All versions | 4.1.0 |
| `github.com/babylonlabs-io/babylon/v4` | Go | All versions | 4.1.0 |
| `github.com/babylonlabs-io/babylon` | Go | All versions | None |
| `github.com/babylonlabs-io/babylon/v2` | Go | All versions | None |
| `github.com/babylonlabs-io/babylon/v3` | Go | All versions | None |

## How do I fix GHSA-2fcv-qww3-9v6h?

Upgrade github.com/babylonlabs-io/babylon/v4 to 4.1.0 or later.

## Is GHSA-2fcv-qww3-9v6h being exploited?

There is no known exploitation of GHSA-2fcv-qww3-9v6h in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for GHSA-2fcv-qww3-9v6h and fix it if it is affected.

What it is: GHSA-2fcv-qww3-9v6h is a denial of service vulnerability in github.com/babylonlabs-io/babylon, published on 24 Nov 2025. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of GHSA-2fcv-qww3-9v6h in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/babylonlabs-io/babylon/v4 (Go): affected all versions; fixed in 4.1.0
- github.com/babylonlabs-io/babylon/v4 (Go): affected all versions; fixed in 4.1.0
- github.com/babylonlabs-io/babylon/v4 (Go): affected all versions; fixed in 4.1.0
- github.com/babylonlabs-io/babylon (Go): affected all versions; no fix listed
- github.com/babylonlabs-io/babylon/v2 (Go): affected all versions; no fix listed
- github.com/babylonlabs-io/babylon/v3 (Go): affected all versions; no fix listed

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/GHSA-2fcv-qww3-9v6h/ (Markdown: https://insights.sbomify.com/GHSA-2fcv-qww3-9v6h/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/GHSA-2fcv-qww3-9v6h

---
From sbomify Insights: https://insights.sbomify.com/GHSA-2fcv-qww3-9v6h/
Summaries are generated and may contain mistakes; the official description above is the record.