CVE-2026-18871: Power System Buffer Overflow

Severity: high (CVSS 7.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-19 · updated 2026-08-25
Weakness: CWE-121

Description

IBM PowerVM Hypervisor FW1120.00, FW1110.00 through FW1110.30, and FW1060.00 through FW1060.80 is affected by a vulnerability in host firmware configuration parsing. An attacker with authenticated service-level access to the service processor can write specially crafted configuration data, causing the host firmware boot stack to crash with possible memory corruption during system initialisation, resulting in an integrity and availability impact to the managed system.

Affected products

IBM Power System E1050 (9043-Mrx) Firmware: from fw1060.00 before fw1060.81 — fixed in fw1060.81
IBM Power System E1080 (9080-Hex) Firmware: from fw1060.00 before fw1060.81 — fixed in fw1060.81
IBM Power System E1150 (9043-Mru) Firmware: from fw1110.00 before fw1110.31; fw1120.00 — fixed in fw1110.31
IBM Power System E1180 (9080-Heu) Firmware: from fw1110.00 before fw1110.31; fw1120.00 — fixed in fw1110.31
IBM Power System L1022 (9786-22H) Firmware: from fw1060.00 before fw1060.81 — fixed in fw1060.81
IBM Power System L1024 (9786-42H) Firmware: from fw1060.00 before fw1060.81 — fixed in fw1060.81
IBM Power System L1122 (9856-22H) Firmware: from fw1110.00 before fw1110.31; fw1120.00 — fixed in fw1110.31
IBM Power System L1124 (9856-42H) Firmware: from fw1110.00 before fw1110.31; fw1120.00 — fixed in fw1110.31
IBM Power System S1012 (9028-21B) Firmware: from fw1060.00 before fw1060.81 — fixed in fw1060.81
IBM Power System S1014 (9105-41B) Firmware: from fw1060.00 before fw1060.81 — fixed in fw1060.81
IBM Power System S1022 (9105-22A) Firmware: from fw1060.00 before fw1060.81 — fixed in fw1060.81
IBM Power System S1022S (9105-22B) Firmware: from fw1060.00 before fw1060.81 — fixed in fw1060.81
IBM Power System S1024 (9105-42A) Firmware: from fw1060.00 before fw1060.81 — fixed in fw1060.81
IBM Power System S1112 (9242-21B) Firmware: fw1120.00
IBM Power System S1112 (9242-21T) Firmware: fw1120.00
IBM Power System S1114 (9824-41B) Firmware: from fw1110.00 before fw1110.31; fw1120.00 — fixed in fw1110.31
IBM Power System S1122 (9824-22A) Firmware: from fw1110.00 before fw1110.31; fw1120.00 — fixed in fw1110.31
IBM Power System S1122S (9824-22B) Firmware: from fw1110.00 before fw1110.31; fw1120.00 — fixed in fw1110.31
IBM Power System S1124 (9824-42A) Firmware: from fw1110.00 before fw1110.31; fw1120.00 — fixed in fw1110.31

How to fix

Upgrade to a fixed version: IBM Power System E1050 (9043-Mrx) Firmware fw1060.81; IBM Power System E1080 (9080-Hex) Firmware fw1060.81; IBM Power System E1150 (9043-Mru) Firmware fw1110.31; IBM Power System E1180 (9080-Heu) Firmware fw1110.31; IBM Power System L1022 (9786-22H) Firmware fw1060.81; IBM Power System L1024 (9786-42H) Firmware fw1060.81; IBM Power System L1122 (9856-22H) Firmware fw1110.31; IBM Power System L1124 (9856-42H) Firmware fw1110.31; IBM Power System S1012 (9028-21B) Firmware fw1060.81; IBM Power System S1014 (9105-41B) Firmware fw1060.81; IBM Power System S1022 (9105-22A) Firmware fw1060.81; IBM Power System S1022S (9105-22B) Firmware fw1060.81. Check the vendor advisory for mitigations.

References

https://www.ibm.com/support/pages/node/7283238

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