What is CVE-2026-18871?

CVE-2026-18871 is a high-severity vulnerability in IBM Powervm Hypervisor, classified under Stack-based Buffer Overflow. CVSS score: 7.3/10. Published 2026-08-19.

How severe is CVE-2026-18871?

High severity. CVSS v3 base score is 7.3 out of 10.

Buffer overflow in IBM Powervm Hypervisor

CVE-2026-18871

IBM PowerVM Hypervisor FW1120.00, FW1110.00 through FW1110.30, and FW1060.00 through FW1060.80 is affected by a vulnerability in host firmware configuration parsing. An attacker with authenticated service-level access to the service processor can write specially crafted configuration data, causing the host firmware boot stack to crash with possible memory corruption during system initialisation, resulting in an integrity and availability impact to the managed system.

Vulnerability class: Buffer Overflow

CVSS v3 metric

CVSS v3 base score 7.3 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:H.

Affected products

Ibm Powervm Hypervisor — versions FW1120.00

Weakness classification (CWE)

CWE-121 — Stack-based Buffer Overflow

References

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

Frequently asked questions

What is CVE-2026-18871?: CVE-2026-18871 is a high-severity vulnerability in IBM Powervm Hypervisor, classified under Stack-based Buffer Overflow. CVSS score: 7.3/10. Published 2026-08-19.
How severe is CVE-2026-18871?: High severity. CVSS v3 base score is 7.3 out of 10.