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.

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

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.

Affected products

Ibm Mq For Hpe Nonstop

Weakness classification (CWE)

CWE-122 — Heap-based Buffer Overflow

References

psirt@us.ibm.com (vendor-advisory, patch)

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.