Out-of-bounds Read in IBM Power System E1050 \(9043-Mrx\) Firmware

CVE-2026-16707

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 service processor mailbox interface. An attacker with authenticated service-level access to the FSP can send a specially crafted mailbox message to read or modify arbitrary regions of Hostboot memory, compromising the host firmware boot stack and the hypervisor subsequently loaded by it. Successful exploitation results in a confidentiality, integrity, and availability impact to the managed system.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.002 (5.6th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 6th percentile — 5.6% 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-2026-16707: held from 0.001 to 0.002.

EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-16707?
CVE-2026-16707 is a high-severity vulnerability in IBM Power System E1050 \(9043-Mrx\) Firmware, classified under Out-of-bounds Read. CVSS score: 8.2/10. Published 2026-08-19.
How severe is CVE-2026-16707?
High severity. CVSS v3 base score is 8.2 out of 10.