# CVE-2026-11726: IBM MQ for HPE NonStop out-of-bounds read in message header

Source: https://junglewise.ai/threats/cve-2026-11726-ibm-mq-for-hpe-nonstop-8-1-0-through-8-1-0-40-could-allow-an  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-18. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-11726 · Severity: high · CVSS 8.1 · Published 2026-09-18

IBM MQ for HPE NonStop is a message queueing system used for enterprise integration in mission-critical environments. An authenticated attacker can exploit improper validation of message header offsets to read sensitive data from memory or crash the service, causing business disruptions. The vulnerability requires valid credentials to exploit but poses significant risk to confidentiality and availability.

Technologies: [IBM MQ for HPE NonStop](https://junglewise.ai/threats/technologies/mq-for-hpe-nonstop). Vendors: [IBM](https://junglewise.ai/threats/vendors/ibm).

## Quick answers

**Is CVE-2026-11726 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-11726 being exploited in the wild.

**How severe is CVE-2026-11726?** High severity, with a CVSS score of 8.1, published 18 September 2026.

**Which products and versions are affected?** IBM MQ for HPE NonStop 8.1.0 through 8.1.0.40.

**Is there a fix for CVE-2026-11726?** A patch was published on 2026-09-17: CSU 8.1.0.41 available Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-11726 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-11726?** Check whether you run IBM MQ for HPE NonStop at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability is an out-of-bounds read (CWE-125) in message header processing due to improper validation of header offset values. Attack vector is network-based, requires authentication (PR:L), and no user interaction. An attacker can trigger information disclosure or denial of service. A patch is available via CSU 8.1.0.41.

## Affected products

- IBM MQ for HPE NonStop 8.1.0 through 8.1.0.40

## Timeline

- 2026-09-17: disclosed
- 2026-09-17: patched: CSU 8.1.0.41 available

## References

- [https://www.ibm.com/support/pages/node/7287707](https://www.ibm.com/support/pages/node/7287707)

## Related threats

- [IBM MQ for HPE NonStop C client heap overflow in AMS policy handling](https://junglewise.ai/threats/cve-2026-11727-ibm-mq-for-hpe-nonstop-8-1-0-through-8-1-0-40-ibm-mq-c-client)
- [IBM MQ for HPE NonStop heap buffer overflow in cluster migration](https://junglewise.ai/threats/cve-2026-11716-ibm-mq-for-hpe-nonstop-8-1-0-through-8-1-0-40-could-allow-an)
- [IBM MQ heap-based buffer overflow in distribution lists](https://junglewise.ai/threats/cve-2026-11381-ibm-mq-could-allow-an-authenticated-attacker-to-cause-a-denial-of)
- [IBM MQ for HPE NonStop heap buffer underflow in message processing](https://junglewise.ai/threats/cve-2026-10858-ibm-mq-for-hpe-nonstop-8-1-0-through-8-1-0-40-could-allow-an)
- [IBM MQ for HPE NonStop integer overflow in MQINQ validation](https://junglewise.ai/threats/cve-2026-10744-ibm-mq-for-hpe-nonstop-integer-overflow-in-mqinq-validation)