CVE-2026-17042: Power System Out-of-bounds Read

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-125

Description

IBM Power Systems Firmware FW950.00 through FW950.H2, OP940.00 through OP940.a1 (Power9), and OP940.00 - OP940.81 (Power HMC) is affected by a vulnerability in host firmware NVRAM parsing. An attacker with root access to a guest partition on an OpenPOWER system can write a specially crafted NVRAM image, causing the host firmware boot stage to crash with possible memory corruption. This condition persists until operator intervention — clearing NVRAM via the service processor — to restore normal operation. This vulnerability only affects OpenPOWER systems; systems running PowerVM are not affected. Successful exploitation results in an integrity and availability impact to the managed system.

Affected products

IBM Power Hardware Management Console (7063-Cr2) Firmware: from op940 before op940.82 — fixed in op940.82
IBM Power System Ac922 (8335-Gth) Firmware: from op940 before op940.a2 — fixed in op940.a2
IBM Power System Ac922 (8335-Gtx) Firmware: from op940 before op940.a2 — fixed in op940.a2
IBM Power System E950 (9040-Mr9) Firmware: from fw950.00 before fw950.h3 — fixed in fw950.h3
IBM Power System E980 (9080-M9S) Firmware: from fw950.00 before fw950.h3 — fixed in fw950.h3
IBM Power System H922 (9223-22S) Firmware: from fw950.00 before fw950.h3 — fixed in fw950.h3
IBM Power System H924 (9223-42S) Firmware: from fw950.00 before fw950.h3 — fixed in fw950.h3
IBM Power System S914 (9009-41G) Firmware: from fw950.00 before fw950.h3 — fixed in fw950.h3
IBM Power System S922 (9009-22G) Firmware: from fw950.00 before fw950.h3 — fixed in fw950.h3
IBM Power System S924 (9009-42G) Firmware: from fw950.00 before fw950.h3 — fixed in fw950.h3

How to fix

Upgrade to a fixed version: IBM Power Hardware Management Console (7063-Cr2) Firmware op940.82; IBM Power System Ac922 (8335-Gth) Firmware op940.a2; IBM Power System Ac922 (8335-Gtx) Firmware op940.a2; IBM Power System E950 (9040-Mr9) Firmware fw950.h3; IBM Power System E980 (9080-M9S) Firmware fw950.h3; IBM Power System H922 (9223-22S) Firmware fw950.h3; IBM Power System H924 (9223-42S) Firmware fw950.h3; IBM Power System S914 (9009-41G) Firmware fw950.h3; IBM Power System S922 (9009-22G) Firmware fw950.h3; IBM Power System S924 (9009-42G) Firmware fw950.h3. Check the vendor advisory for mitigations.

References

https://www.ibm.com/support/pages/node/7283240

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