# CVE-2025-54126: WebAssembly Micro Runtime's `--addr-pool` option allows all IPv4 addresses when subnet mask is not specified

> WAMR's iwasm allows all IPv4 addresses when --addr-pool lacks a subnet mask, potentially exposing services to unauthorized access.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 29 Jul 2025
- **Updated:** 30 Jul 2025
- **Also known as:** AZL-66045, AZL-66048, GHSA-vh64-mfvw-pxqp

## What is CVE-2025-54126?

CVE-2025-54126 is a medium-severity vulnerability in bytecodealliance wasm-micro-runtime, published on 29 Jul 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The WebAssembly Micro Runtime's (WAMR) iwasm package is the executable binary built with WAMR VMcore which supports WebAssembly System Interface (WASI) and command line interface. In versions 2.4.0 and below, iwasm uses --addr-pool with an IPv4 address that lacks a subnet mask, allowing the system to accept all IP addresses. This can unintentionally expose the service to all incoming connections and bypass intended access restrictions. Services relying on --addr-pool for restricting access by IP may unintentionally become open to all external connections. This may lead to unauthorized access in production deployments, especially when users assume that specifying an IP without a subnet mask implies a default secure configuration. This is fixed in version 2.4.1.

Weakness: CWE-668 (Exposure of Resource to Wrong Sphere)

## Which versions are affected by CVE-2025-54126?

It affects 1 product.


Products: Bytecodealliance Webassembly Micro Runtime.

## How do I fix CVE-2025-54126?

Upgrade to a fixed version.

## Is CVE-2025-54126 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-54126 exists.

## Other vulnerabilities in bytecodealliance wasm-micro-runtime

- [CVE-2024-25431](https://insights.sbomify.com/CVE-2024-25431/): Memory corruption in n/a (high 8.8)
- [CVE-2024-27532](https://insights.sbomify.com/CVE-2024-27532/): Null dereference in n/a (high 7.5)
- [CVE-2024-34251](https://insights.sbomify.com/CVE-2024-34251/): Memory corruption in n/a (high 7.5)
- [CVE-2023-48105](https://insights.sbomify.com/CVE-2023-48105/): Memory corruption in n/a (high 7.5)
- [CVE-2025-43853](https://insights.sbomify.com/CVE-2025-43853/): iwasm vulnerable to filesystem sandbox escape with symlink when using uvwasi feature (high 7.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-54126 and fix it if it is affected.

What it is: CVE-2025-54126 is a medium-severity vulnerability in bytecodealliance wasm-micro-runtime, published on 29 Jul 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-54126 exists.

Affected product: bytecodealliance wasm-micro-runtime. 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-2025-54126/ (Markdown: https://insights.sbomify.com/CVE-2025-54126/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-54126
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-54126
- OSV: https://osv.dev/vulnerability/CVE-2025-54126

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-54126/
Summaries are generated and may contain mistakes; the official description above is the record.