CVE-2026-18871 Power System Buffer Overflow

High 7.3 Published 19 Aug 2026 Updated 20 Aug 2026

An attacker with service-level access can cause memory corruption and system crashes via crafted firmware configuration data.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Local or same network only
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-18871?

CVE-2026-18871 is a high-severity memory corruption vulnerability in IBM PowerVM Hypervisor, published on 19 Aug 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, 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.

Weakness: CWE-121

Which versions are affected by CVE-2026-18871?

It affects 19 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 L1022 \(9786-22h\) Firmware, Ibm Power System L1024 \(9786-42h\) Firmware and 13 more.

How do I fix CVE-2026-18871?

No fix has been published for CVE-2026-18871 yet. Limit exposure of the affected software until one is available.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2026-18871 being exploited?

There is no known exploitation of CVE-2026-18871 in the wild and no public exploit code.

Sources

Also known as GHSA-28wc-xwjr-q8gm.