Power System Out-of-bounds Write
Summary
| CVE | CVE-2026-18821 |
|---|---|
| State | PUBLISHED |
| Assigner | ibm |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-08-19 20:17:13 UTC |
| Updated | 2026-08-22 04:17:41 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 7.5 HIGH from [email protected]
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS: 0.001910000 probability, percentile 0.090580000 (date 2026-08-21)
Problem Types: CWE-787 | CWE-787 CWE-787 Out-of-bounds Write
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 7.5 | HIGH | CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | CNA | CVSS | 7.5 | HIGH | CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
CVSS v3.1 Breakdown
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | IBM | PowerVM Hypervisor | affected FW1120.00 | Not specified |
| CNA | IBM | PowerVM Hypervisor | affected FW1110.00 FW1110.30 semver | Not specified |
| CNA | IBM | PowerVM Hypervisor | affected FW1060.00 FW1060.80 semver | Not specified |
| CNA | IBM | PowerVM Hypervisor | affected FW950.00 FW950.H2 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| www.ibm.com/support/pages/node/7283232 | [email protected] | www.ibm.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Additional Advisory Data
Solutions
CNA: Customers with the products below should install FW1110.31(1110_134), FW1120.01(1120_167), or newer to remediate this vulnerability. Power 11 * IBM Power System E1180 (9080-HEU) Customers with the products below should install FW1110.31(1110_155), FW1120.01(1120_190), or newer to remediate this vulnerability. Power 11 * IBM Power System S1122 (9824-22A) * IBM Power System S1124 (9824-42A) * IBM Power System S1122s (9824-22B) * IBM Power System S1114 (9824-41B) * IBM Power System L1122 (9856-22H) * IBM Power System L1124 (9856-42H) * IBM Power System E1150 (9043-MRU) Customers with the products below should install FW1120.01(1120_190), or newer to remediate this vulnerability. Power 11 * IBM Power System S1112 (9242-21B, 9242-21T) Customers with the products below should install FW1060.81(1060_184), or newer to remediate this vulnerability. Power 10 * IBM Power System E1080 (9080-HEX) Customers with the products below should install FW1060.81(1060_191), or newer to remediate this vulnerability. Power 10 * IBM Power System S1022 (9105-22A) * IBM Power System S1024 (9105-42A) * IBM Power System S1022s (9105-22B) * IBM Power System S1014 (9105-41B) * IBM Power System L1022 (9786-22H) * IBM Power System L1024 (9786-42H) * IBM Power System E1050 (9043-MRX) * IBM Power System S1012 (9028-21B) Customers with the products below should install FW950.H3(950_230) or newer to remediate this vulnerability. Power 9 * IBM Power System S922 (9009-22G) * IBM Power System H922 (9223-22S) * IBM Power System S914 (9009-41G) * IBM Power System S924 (9009-42G) * IBM Power System H924 (9223-42S) * IBM Power System E950 (9040-MR9) * IBM Power System E980 (9080-M9S) The images mentioned above can be located at IBM Fix Central : https://www.ibm.com/support/fixcentral/ https://www.ibm.com/support/fixcentral/