Buffer overflow in IBM Mq For HPE Nonstop

CVE-2026-10858

IBM MQ for HPE NonStop 8.1.0 through 8.1.0.40 could allow an authenticated attacker to cause a denial of service or potentially execute arbitrary code due to a heap buffer underflow when processing multi-segment messages.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.9 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.006 (48.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 48th percentile — 48.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-10858: held from 0.004 to 0.006.

EPSS over last 30 days · oldest: 0.004 · newest: 0.006 · change: +0.002

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-10858?
CVE-2026-10858 is a critical-severity vulnerability in IBM Mq For HPE Nonstop, classified under Heap-based Buffer Overflow. CVSS score: 9.9/10. Published 2026-09-18.
How severe is CVE-2026-10858?
Critical severity. CVSS v3 base score is 9.9 out of 10.