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

Medium 6.9 Published 29 Jul 2025 Updated 30 Jul 2025

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

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

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

Which versions are affected by CVE-2025-54126?

It affects 1 product.

Products include 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.

Sources

Also known as AZL-66045, AZL-66048, GHSA-vh64-mfvw-pxqp.