---
id: "CVE-2026-12155"
kind: "vulnerability"
aliases: ["CVE-2026-12155"]
title: "IBM MQ Operator: crafted multicast messages crash the queue manager"
severity: "medium"
cvss: 6.5
epss: null
exploited: false
status: "open"
category: "vendor"
products: [{"name": "ibm mq operator", "fixed": [], "affected": ">= 2.0.0, <= 2.0.29", "ecosystem": "vendor"}, {"name": "ibm mq operator", "fixed": [], "affected": ">= 3.2.0, <= 3.2.29", "ecosystem": "vendor"}, {"name": "ibm mq operator", "fixed": [], "affected": "= 3.3.0", "ecosystem": "vendor"}, {"name": "ibm mq operator", "fixed": [], "affected": "= 3.4.0", "ecosystem": "vendor"}, {"name": "ibm mq operator", "fixed": [], "affected": "= 3.4.1", "ecosystem": "vendor"}, {"name": "ibm mq operator", "fixed": [], "affected": "= 3.5.0", "ecosystem": "vendor"}, {"name": "ibm mq operator", "fixed": [], "affected": "= 3.5.1", "ecosystem": "vendor"}, {"name": "ibm mq operator", "fixed": [], "affected": "= 3.5.2", "ecosystem": "vendor"}, {"name": "ibm mq operator", "fixed": [], "affected": "= 3.5.3", "ecosystem": "vendor"}, {"name": "ibm mq operator", "fixed": [], "affected": "= 3.6.0", "ecosystem": "vendor"}, {"name": "ibm mq operator", "fixed": [], "affected": "= 3.6.1", "ecosystem": "vendor"}, {"name": "ibm mq operator", "fixed": [], "affected": "= 3.6.2", "ecosystem": "vendor"}, {"name": "ibm mq operator", "fixed": [], "affected": "= 3.6.3", "ecosystem": "vendor"}, {"name": "ibm mq operator", "fixed": [], "affected": "= 3.6.4", "ecosystem": "vendor"}, {"name": "ibm mq operator", "fixed": [], "affected": "= 3.7.0", "ecosystem": "vendor"}, {"name": "ibm mq operator", "fixed": [], "affected": "= 3.7.1", "ecosystem": "vendor"}, {"name": "ibm mq operator", "fixed": [], "affected": "= 3.7.2", "ecosystem": "vendor"}, {"name": "ibm mq operator", "fixed": [], "affected": "= 3.8.0", "ecosystem": "vendor"}, {"name": "ibm mq operator", "fixed": [], "affected": "= 3.8.1", "ecosystem": "vendor"}, {"name": "ibm mq operator", "fixed": [], "affected": "= 3.9.0", "ecosystem": "vendor"}, {"name": "ibm mq operator", "fixed": [], "affected": "= 3.9.1", "ecosystem": "vendor"}, {"name": "ibm mq operator", "fixed": [], "affected": "= 3.9.2", "ecosystem": "vendor"}, {"name": "ibm mq operator", "fixed": [], "affected": "= 4.0.0", "ecosystem": "vendor"}, {"name": "ibm mq operator", "fixed": [], "affected": "= 4.0.1", "ecosystem": "vendor"}, {"name": "ibm mq operator", "fixed": [], "affected": "= 4.0.2", "ecosystem": "vendor"}, {"name": "ibm mq operator", "fixed": [], "affected": "= 4.0.3", "ecosystem": "vendor"}, {"name": "ibm mq operator", "fixed": [], "affected": "= 4.0.4", "ecosystem": "vendor"}, {"name": "ibm supplied mq advanced container images", "fixed": [], "affected": "= 9.4.1.0", "ecosystem": "vendor"}, {"name": "ibm supplied mq advanced container images", "fixed": [], "affected": "= 9.4.1.1", "ecosystem": "vendor"}, {"name": "ibm supplied mq advanced container images", "fixed": [], "affected": "= 9.4.2.0", "ecosystem": "vendor"}, {"name": "ibm supplied mq advanced container images", "fixed": [], "affected": "= 9.4.2.1", "ecosystem": "vendor"}, {"name": "ibm supplied mq advanced container images", "fixed": [], "affected": "= 9.4.3.0", "ecosystem": "vendor"}, {"name": "ibm supplied mq advanced container images", "fixed": [], "affected": "= 9.4.3.1", "ecosystem": "vendor"}, {"name": "ibm supplied mq advanced container images", "fixed": [], "affected": "= 9.4.4.0", "ecosystem": "vendor"}, {"name": "ibm supplied mq advanced container images", "fixed": [], "affected": "= 9.4.4.1", "ecosystem": "vendor"}, {"name": "ibm supplied mq advanced container images", "fixed": [], "affected": "= 9.4.5.0", "ecosystem": "vendor"}, {"name": "ibm supplied mq advanced container images", "fixed": [], "affected": "= 9.4.5.1", "ecosystem": "vendor"}, {"name": "ibm supplied mq advanced container images", "fixed": [], "affected": "= 10.0.0.0", "ecosystem": "vendor"}, {"name": "ibm supplied mq advanced container images", "fixed": [], "affected": "= 10.0.0.5", "ecosystem": "vendor"}, {"name": "ibm supplied mq advanced container images", "fixed": [], "affected": "= 9.3.0.0", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["ibm-mq", "kubernetes", "messaging", "openshift", "vendor"]
not_affected_if: ["auth-required", "not-using-mq-operator"]
published_at: "2026-10-19T17:17:17+00:00"
first_seen_at: "2026-10-23T21:57:18+00:00"
updated_at: "2026-10-25T03:55:51+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-12155", "first_seen_at": "2026-10-23T21:57:18+00:00"}]
---

# IBM MQ Operator: crafted multicast messages crash the queue manager

IBM MQ Operator versions in several ranges mishandle specially crafted multicast status messages, causing a NULL pointer dereference. An authenticated attacker can use this to cause a denial of service.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:ibm mq operator affected >= 2.0.0, <= 2.0.29 fixed ?
- vendor:ibm mq operator affected >= 3.2.0, <= 3.2.29 fixed ?
- vendor:ibm mq operator affected = 3.3.0 fixed ?
- vendor:ibm mq operator affected = 3.4.0 fixed ?
- vendor:ibm mq operator affected = 3.4.1 fixed ?
- vendor:ibm mq operator affected = 3.5.0 fixed ?
- vendor:ibm mq operator affected = 3.5.1 fixed ?
- vendor:ibm mq operator affected = 3.5.2 fixed ?
- vendor:ibm mq operator affected = 3.5.3 fixed ?
- vendor:ibm mq operator affected = 3.6.0 fixed ?
- vendor:ibm mq operator affected = 3.6.1 fixed ?
- vendor:ibm mq operator affected = 3.6.2 fixed ?
- vendor:ibm mq operator affected = 3.6.3 fixed ?
- vendor:ibm mq operator affected = 3.6.4 fixed ?
- vendor:ibm mq operator affected = 3.7.0 fixed ?
- vendor:ibm mq operator affected = 3.7.1 fixed ?
- vendor:ibm mq operator affected = 3.7.2 fixed ?
- vendor:ibm mq operator affected = 3.8.0 fixed ?
- vendor:ibm mq operator affected = 3.8.1 fixed ?
- vendor:ibm mq operator affected = 3.9.0 fixed ?
- vendor:ibm mq operator affected = 3.9.1 fixed ?
- vendor:ibm mq operator affected = 3.9.2 fixed ?
- vendor:ibm mq operator affected = 4.0.0 fixed ?
- vendor:ibm mq operator affected = 4.0.1 fixed ?
- vendor:ibm mq operator affected = 4.0.2 fixed ?
- vendor:ibm mq operator affected = 4.0.3 fixed ?
- vendor:ibm mq operator affected = 4.0.4 fixed ?
- vendor:ibm supplied mq advanced container images affected = 9.4.1.0 fixed ?
- vendor:ibm supplied mq advanced container images affected = 9.4.1.1 fixed ?
- vendor:ibm supplied mq advanced container images affected = 9.4.2.0 fixed ?
- vendor:ibm supplied mq advanced container images affected = 9.4.2.1 fixed ?
- vendor:ibm supplied mq advanced container images affected = 9.4.3.0 fixed ?
- vendor:ibm supplied mq advanced container images affected = 9.4.3.1 fixed ?
- vendor:ibm supplied mq advanced container images affected = 9.4.4.0 fixed ?
- vendor:ibm supplied mq advanced container images affected = 9.4.4.1 fixed ?
- vendor:ibm supplied mq advanced container images affected = 9.4.5.0 fixed ?
- vendor:ibm supplied mq advanced container images affected = 9.4.5.1 fixed ?
- vendor:ibm supplied mq advanced container images affected = 10.0.0.0 fixed ?
- vendor:ibm supplied mq advanced container images affected = 10.0.0.5 fixed ?
- vendor:ibm supplied mq advanced container images affected = 9.3.0.0 fixed ?

## How to check

- Check the installed IBM MQ Operator version (for example with `oc get csv` or `kubectl get csv` in the operator namespace) and compare it with the affected ranges: 2.0.0 to 2.0.29, 3.2.0 to 3.2.29, and 3.3.0 to 3.6.2 (specific listed versions).
- unknown whether the multicast status feature must be enabled for exposure

## Fix

- Move IBM MQ Operator to a fixed release listed in the IBM security bulletin for CVE-2026-12155; the sources do not name the fixed version numbers.

## Timeline

- 2026-10-23T21:57:18+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-12155

## From the sources

IBM MQ could allow an authenticated attacker to cause a denial of service by sending specially crafted multicast status messages that trigger a NULL pointer dereference.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_