CVE-2026-17503 This Power System update is being released to address

Medium 5.1 Published 24 Sep 2026 Updated 24 Sep 2026

An attacker with root access can corrupt partition NVRAM, causing the partition to fail to boot until manual operator intervention restores the configuration.

Exploited in the wild: Not known
Login needed: An administrator
Attackable: Local or same network only
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-17503?

CVE-2026-17503 is a medium-severity denial of service vulnerability in IBM PowerVM Hypervisor, published on 24 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

IBM PowerVM Hypervisor FW1120.00 through FW1120.01, FW1110.00 through FW1110.31, FW1060.00 through FW1060.81, and FW950.00 through FW950.H3 is affected by a vulnerability in the partition firmware runtime boot configuration. An attacker with root access to a partition can maliciously alter partition nvram, causing the partition to fail to boot. This condition persists until operator intervention — deleting and recreating the partition configuration — to restore normal operation. Successful exploitation results in an integrity and availability impact.

Weakness: CWE-20

Which versions are affected by CVE-2026-17503?

It affects 26 products.

Products include Ibm Power System E1050 \(9043-Mrx\) Firmware, Ibm Power System E1080 \(9080-Hex\) Firmware, Ibm Power System E1150 \(9043-Mru\) Firmware, Ibm Power System E1180 \(9080-Heu\) Firmware, Ibm Power System E950 \(9040-Mr9\) Firmware, Ibm Power System E980 \(9080-M9s\) Firmware and 20 more.

How do I fix CVE-2026-17503?

No fix has been published for CVE-2026-17503 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2026-17503 being exploited?

There is no known exploitation of CVE-2026-17503 in the wild and no public exploit code.

Sources

Also known as GHSA-c8jr-2gj7-xxh3.