CVE-2026-108946: Input Validation Flaw (CVSS 6.5)

Description

Improper input validation vulnerability in Apache ActiveMQ, Apache ActiveMQ KahaDB. The ActiveMQ broker resolves connection, session and consumer state from ids that are user provided and in some scenarios does not validate that they ids are bound to that user. This allows an authenticated client to spoof another user's ids. This allows: * an authenticated client consumes from another connection's temporary queue/topic by putting the victim's connection id in its own ConsumerId, bypassing the broker-side ownership check. * a duplicate ConsumerId registration is only logged, after which the attacker's RemoveInfo or disconnect tears down the victim's live subscription * a forged MessageAck for the victim's ConsumerId permanently deletes an in-flight, unacknowledged message. This issue affects Apache ActiveMQ: from 6.0.0 before 6.3.3, before 5.19.12; Apache ActiveMQ KahaDB: from 6.0.0 before 6.3.3, before 5.19.12. Users are recommended to upgrade to version 6.4.0, 6.3.3, or 5.19.12, which fixes the issue.

Is your site exposed to CVE-2026-108946?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

6.5

MEDIUM

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

EPSS — Exploit Prediction

0.0039

Probability of exploitation

0.33%

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-20 Improper Input Validation

References

Other References

https://lists.apache.org/thread/0spj0m846vhw3cjyfmzsy3l8vxh6f5t6 http://www.openwall.com/lists/oss-security/2026/11/03/17

Frequently Asked Questions

What is CVE-2026-108946? +

Improper input validation vulnerability in Apache ActiveMQ, Apache ActiveMQ KahaDB. The ActiveMQ broker resolves connection, session and consumer state from ids that are user provided and in some scenarios does not validate that they ids are bound to that user. This allows an authenticated client to spoof another user's ids. This allows: * an authenticated client consumes from another connection's temporary queue/topic by putting the victim's connection id in its own ConsumerId, bypassing the broker-side ownership check. * a duplicate ConsumerId registration is only logged, after which the attacker's RemoveInfo or disconnect tears down the victim's live subscription * a forged MessageAck for the victim's ConsumerId permanently deletes an in-flight, unacknowledged message. This issue affects Apache ActiveMQ: from 6.0.0 before 6.3.3, before 5.19.12; Apache ActiveMQ KahaDB: from 6.0.0 before 6.3.3, before 5.19.12. Users are recommended to upgrade to version 6.4.0, 6.3.3, or 5.19.12, which fixes the issue. It has a CVSS v3.1 base score of 6.5 (MEDIUM).

How severe is CVE-2026-108946? +

CVE-2026-108946 has a CVSS v3.1 score of 6.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0039, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-108946? +

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.

Related Vulnerabilities

CVE-2025-13826

Zervit's portable HTTP/web server is vulnerable to remote DoS attacks when a configuration reset request is made. The vulnerability is …

CVE-2026-62658

A security flaw was discovered in certain NETGEAR Nighthawk RAX series routers that could allow someone already logged in to …

CVE-2024-54011

Penetration Testing engineers at Amazon have discovered a flaw where the camera system fails to properly handle data supplied in …

CVE-2026-54700

ConnectBot SSH Client Library is written in Kotlin with Kaitai Struct and KStateMachine. Prior to 0.3.1, the SSH protocol parser …

CVE-2026-56349

n8n before version 2.10.0 contains an input validation vulnerability in the Guardrail node that allows attackers to bypass default guardrail …

CVE-2026-6409

A Denial of Service (DoS) vulnerability exists in the Protobuf PHP library during the parsing of untrusted input. Maliciously structured …

CVE-2026-108946