SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-18821

IBM PowerVM Hypervisor FW1120.00, FW1110.00 through FW1110.30, FW1060.00 through FW1060.80, and FW950.00 through FW950.H2 Power Systems Firmware is affected by a vulnerability in partition firmware during network boot.

HIGH 8.8EPSS 0.29%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.29%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

IBM PowerVM Hypervisor FW1120.00, FW1110.00 through FW1110.30, FW1060.00 through FW1060.80, and FW950.00 through FW950.H2 Power Systems Firmware is affected by a vulnerability in partition firmware during network boot. An unauthenticated attacker on the same network as a partition undergoing network boot can send a malformed packet, allowing arbitrary code to be executed in the partition firmware and compromising everything subsequently loaded by that partition. Other partitions and the managed system are not affected. Only partitions actively performing a network boot are affected, resulting in a confidentiality, integrity, and availability impact.

CVSS 3.1
8.8 HIGHCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
0.29% probability · 21th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-787
Affected
ibm/power system s1122 \(9824-22a\) firmware · ibm/power system s1124 \(9824-42a\) firmware · ibm/power system s1122s \(9824-22b\) firmware · ibm/power system s1114 \(9824-41b\) firmware · ibm/power system l1122 \(9856-22h\) firmware · ibm/power system l1124 \(9856-42h\) firmware · ibm/power system e1150 \(9043-mru\) firmware · ibm/power system s1112 \(9242-21b\) firmware · ibm/power system s1112 \(9242-21t\) firmware · ibm/power system e1080 \(9080-hex\) firmware · ibm/power system s1022 \(9105-22a\) firmware · ibm/power system s1024 \(9105-42a\) firmware · ibm/power system s1022s \(9105-22b\) firmware · ibm/power system s1014 \(9105-41b\) firmware · ibm/power system l1022 \(9786-22h\) firmware · ibm/power system l1024 \(9786-42h\) firmware · ibm/power system e1050 \(9043-mrx\) firmware · ibm/power system s1012 \(9028-21b\) firmware · ibm/power system e1180 \(9080-heu\) firmware · ibm/power system s922 \(9009-22g\) firmware · +6 more
Source
psirt@us.ibm.com
EPSS trend
0%3%5%26 October 2026: 0.29%26 October 202626 October 2026

EPSS 0.3% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.