How severe is CVE-2025-29953?

CVE-2025-29953 has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2025-29953?

CVE-2025-29953 affects the following packages: Apache.NMS.ActiveMQ (NuGet). Ecosystems affected: NuGet.

How do I fix CVE-2025-29953?

Update Apache.NMS.ActiveMQ to 2.1.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-29953 is resolved across your whole dependency graph.

How do I detect CVE-2025-29953 in my NuGet dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Apache.NMS.ActiveMQ. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2025-29953 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2025-29953?

O3 pinpoints whether CVE-2025-29953 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2025-29953 actively exploited in the wild?

No public exploit code has been indexed for CVE-2025-29953 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2025-29953?

CVE-2025-29953 has an EPSS (Exploit Prediction Scoring System) score of 1.6%, placing it in the 73th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2025-29953?

CVE-2025-29953 is classified as Deserialization of Untrusted Data (CWE-502). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2025-29953 published, and has it been updated?

CVE-2025-29953 was published on April 18, 2025 and was last updated on March 14, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

.NET NuGet

CVE-2025-29953

CRITICAL

Apache ActiveMQ NMS OpenWire Client Deserialization of Untrusted Data vulnerability

Also known asGHSA-9g64-r942-fvmp

Published

Apr 18, 2025

Updated

Mar 14, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

1.6%probability of exploitation in next 30 days

Lower Risk73th percentile+1.58%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected

.NETApache.NMS.ActiveMQ

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.

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.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
.NETNuGet	`Apache.NMS.ActiveMQ`	all versions	2.1.1

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Apache.NMS.ActiveMQ. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update Apache.NMS.ActiveMQ to 2.1.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-29953 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2025-29953 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2025-29953. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

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 m

O3 Security · Impact-Aware SCA

Is CVE-2025-29953 in your dependencies?

O3 detects CVE-2025-29953 across NuGet dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works