---
title: "CVE-2025-29953: Apache ActiveMQ NMS OpenWire Client Deserialization of Untrusted Data vulnerability"
url: https://erroneo.us/security/cve/CVE-2025-29953/
description: "CVE-2025-29953 (Apache.NMS.ActiveMQ (NuGet)): Deserialization of Untrusted Data vulnerability in Apache ActiveMQ NMS OpenWire Client. This issue affects…"
type: vulnerability-record
section: "Security Digest"
date_published: 2025-04-18
date_modified: 2025-04-23
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2025-29953"
kev: false
cvss: 9.8
epss: 0.02091
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2025-29953: Apache ActiveMQ NMS OpenWire Client Deserialization of Untrusted Data vulnerability

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 2.1% , percentile 81: FIRST’s model estimates a 2.1% chance of exploitation activity in the next 30 days, higher than 81% of all scored CVEs (elevated). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes Apache.NMS.ActiveMQ (NuGet) < 2.1.1, fixed in 2.1.1 . Check your lockfile, including transitive dependencies.

## What it is

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.

## Affected packages

- NuGet `Apache.NMS.ActiveMQ` < 2.1.1 → fixed: 2.1.1

## Affected products (CVE record)

- Apache Software Foundation Apache ActiveMQ NMS OpenWire Client: < 2.1.1

## Severity

- CISA-ADP CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 2.09% probability of exploitation activity in the next 30 days; percentile 81.

## Sources

- [lists.apache.org](https://lists.apache.org/thread/vc1sj9y3056d3kkhcvrs9fyw5w8kpmlx)
- [GitHub Advisory GHSA-9g64-r942-fvmp](https://github.com/advisories/GHSA-9g64-r942-fvmp)
- [CVE.org record CVE-2025-29953](https://www.cve.org/CVERecord?id=CVE-2025-29953)
- [NVD entry CVE-2025-29953](https://nvd.nist.gov/vuln/detail/CVE-2025-29953)
- [openwall.com](http://www.openwall.com/lists/oss-security/2025/04/18/3)
- [github.com](https://github.com/apache/activemq-nms-openwire/commit/8944c41)
- [issues.apache.org](https://issues.apache.org/jira/browse/AMQNET-844)

---
Source page: https://erroneo.us/security/cve/CVE-2025-29953/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt