Buffer overflow in IBM Power System E1050 \(9043-Mrx\) Firmware

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

Published · last modified .

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.

EPSS exploit prediction

EPSS: 0.001 (2.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 3rd percentile — 2.8% 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-2026-18871: held from 0.001 to 0.001.

EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-18871?
CVE-2026-18871 is a high-severity vulnerability in IBM Power System E1050 \(9043-Mrx\) Firmware, 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.