CVE-2026-18821 PUBLISHED

Power System Out-of-bounds Write

Assigner: ibm
Reserved: 04.08.2026 Published: 19.08.2026 Updated: 19.08.2026

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.

Metrics

CVSS Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS Score: 7.5

Product Status

Vendor IBM
Product PowerVM Hypervisor
Versions
  • Version FW1120.00 is affected
  • affected from FW1110.00 to FW1110.30 (incl.)
  • affected from FW1060.00 to FW1060.80 (incl.)
  • affected from FW950.00 to FW950.H2 (incl.)

Solutions

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/

References

Problem Types

  • CWE-787 Out-of-bounds Write CWE