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

CVE-2026-17091

IBM PowerVM Hypervisor FW1120.00, FW1110.00 through FW1110.30, FW1060.00 through FW1060.80, and FW950.00 through FW950.H2 is affected by a vulnerability in the PowerVM hypervisor call interface. An attacker with root access to a guest partition can issue a specially crafted hypervisor call to inject an arbitrary amount of data into hypervisor or partition memory, resulting in either a crash causing a full platform re-IPL and terminating all hosted partitions, or corruption of hypervisor or partition memory. The PowerVM hypervisor will restart automatically; however, repeated exploitation could result in a sustained availability impact. Successful exploitation results in an integrity and availability impact to the managed system.

Vulnerability class: Integer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.4 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H.

EPSS exploit prediction

EPSS: 0.001 (3.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 3rd percentile — 3.5% 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-2026-17091: 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-2026-17091?
CVE-2026-17091 is a high-severity vulnerability in IBM Power System E1050 \(9043-Mrx\) Firmware, classified under Integer Overflow or Wraparound. CVSS score: 8.4/10. Published 2026-08-19.
How severe is CVE-2026-17091?
High severity. CVSS v3 base score is 8.4 out of 10.