CVE-2026-103582

HIGH
Published Nov 4, 2026 Modified Nov 10, 2026 CWE-789

Description

Unbounded memory allocation and missing frame size validation in Apache NMS ActiveMQ (the .NET OpenWire client, package Apache.NMS.ActiveMQ) before 2.3.0. The OpenWire unmarshalling code trusted the frame size and the length and count fields read from the network. It did not enforce a maximum frame size, and it did not check that decoded lengths fit within the frame being read. A malicious or compromised broker, or an attacker able to intercept and modify an unencrypted connection, could send a crafted OpenWire frame with an oversized or negative length. This could cause the client to attempt very large memory allocations, leading to excessive memory consumption, an OutOfMemoryException or an uncaught exception, and a denial of service of the client application. Users are recommended to upgrade to version 2.3.0, which enforces a configurable maximum frame size and validates lengths against the size of the frame being read.

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CVSS v3.1 Score

7.5
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS — Exploit Prediction

0.0052
Probability of exploitation
0.45%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-789 CWE-789

References

Frequently Asked Questions

What is CVE-2026-103582? +
Unbounded memory allocation and missing frame size validation in Apache NMS ActiveMQ (the .NET OpenWire client, package Apache.NMS.ActiveMQ) before 2.3.0. The OpenWire unmarshalling code trusted the frame size and the length and count fields read from the network. It did not enforce a maximum frame size, and it did not check that decoded lengths fit within the frame being read. A malicious or compromised broker, or an attacker able to intercept and modify an unencrypted connection, could send a crafted OpenWire frame with an oversized or negative length. This could cause the client to attempt very large memory allocations, leading to excessive memory consumption, an OutOfMemoryException or an uncaught exception, and a denial of service of the client application. Users are recommended to upgrade to version 2.3.0, which enforces a configurable maximum frame size and validates lengths against the size of the frame being read. It has a CVSS v3.1 base score of 7.5 (HIGH).
How severe is CVE-2026-103582? +
CVE-2026-103582 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0052, placing it in the 0th percentile for exploitation probability.
How do I check if I'm vulnerable to CVE-2026-103582? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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