# CVE-2026-17503: IBM PowerVM Hypervisor partition firmware boot configuration integrity bypass

Source: https://junglewise.ai/threats/cve-2026-17503-ibm-powervm-hypervisor-fw1120-00-through-fw1120-01-fw1110-00  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-24. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-17503 · Severity: medium · CVSS 5.1 · Published 2026-09-24

IBM PowerVM Hypervisor, which manages virtual partitions on Power Systems servers, contains a vulnerability in how it validates partition boot configuration data. An attacker with administrator access to a virtual partition can corrupt the partition's firmware settings to prevent it from booting, causing an outage that requires manual intervention by a system operator to fix. This impacts the availability of virtualized workloads running on affected Power Systems.

Technologies: [IBM PowerVM Hypervisor](https://junglewise.ai/threats/technologies/powervm-hypervisor). Vendors: [IBM](https://junglewise.ai/threats/vendors/ibm).

## Quick answers

**Is CVE-2026-17503 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-17503 being exploited in the wild.

**How severe is CVE-2026-17503?** Medium severity, with a CVSS score of 5.1, published 24 September 2026.

**Which products and versions are affected?** IBM PowerVM Hypervisor FW1120.00-FW1120.01, FW1110.00-FW1110.31, FW1060.00-FW1060.81, FW950.00-FW950.H3.

**Is there a fix for CVE-2026-17503?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-17503 attacked?** It is attacked with local access, in device firmware.

**Am I affected by CVE-2026-17503?** Check whether you run IBM PowerVM Hypervisor at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability exists in the partition firmware runtime boot configuration validation, where improper input validation (CWE-20) allows an attacker with root/high privileges on a partition to maliciously modify partition NVRAM settings. Exploitation requires local access with high privileges to the partition; successful exploitation results in denial of service and integrity impact. Patches are available for all affected firmware versions (FW950.H4+, FW1060.82+, FW1110.32+, FW1120.02+).

## Affected products

- IBM PowerVM Hypervisor FW1120.00-FW1120.01, FW1110.00-FW1110.31, FW1060.00-FW1060.81, FW950.00-FW950.H3

## Timeline

- 2026-09-24: disclosed: IBM Security Bulletin published

## References

- [https://www.ibm.com/support/pages/node/7289133](https://www.ibm.com/support/pages/node/7289133)

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