# CVE-2026-17100: IBM Power Systems Firmware out-of-bounds write in service processor mailbox

Source: https://junglewise.ai/threats/cve-2026-17100-ibm-power-systems-firmware-out-of-bounds-write-in-service  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-19. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-17100 · Severity: high · CVSS 8.2 · Published 2026-08-19

IBM Power Systems firmware contains a vulnerability in the service processor mailbox interface that allows an authenticated attacker with service-level access to the BMC/FSP to execute arbitrary code in the host firmware runtime. Exploitation grants complete control over managed systems, compromising confidentiality, integrity, and availability of business-critical infrastructure.

Technologies: [IBM Power Systems Firmware](https://junglewise.ai/threats/technologies/power-systems-firmware). Vendors: [IBM](https://junglewise.ai/threats/vendors/ibm).

## Quick answers

**Is CVE-2026-17100 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-17100 being exploited in the wild.

**How severe is CVE-2026-17100?** High severity, with a CVSS score of 8.2, published 19 August 2026.

**Which products and versions are affected?** IBM Power Systems Firmware FW1120.00; FW1110.00–FW1110.30; FW1060.00–FW1060.80; FW950.00–FW950.H2; OP940.00–OP940.a1; OP940.00–OP940.81.

**Is there a fix for CVE-2026-17100?** A patch was published on 2026-08-19: Fixed versions released: FW1120.01, FW1110.31, FW1060.81, FW950.H3, OP940.a2, OP940.82 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-17100 attacked?** It is attacked with local access, in device firmware.

**Am I affected by CVE-2026-17100?** Check whether you run IBM Power Systems Firmware 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 is an out-of-bounds write (CWE-787) in the service processor mailbox interface of IBM Power Systems firmware. An attacker with authenticated service-level access to the Baseboard Management Controller (BMC) or FSP (Flexible Service Processor) can trigger this flaw to execute arbitrary code within the host firmware runtime environment. The attack requires valid service-level credentials and local or adjacent access to the BMC/FSP. Successful exploitation results in arbitrary code execution with full system privileges, enabling complete control over the managed system. IBM has released patched firmware versions (FW1120.01, FW1110.31, FW1060.81, FW950.H3, OP940.a2, OP940.82) across affected product lines.

## Affected products

- IBM Power Systems Firmware FW1120.00; FW1110.00–FW1110.30; FW1060.00–FW1060.80; FW950.00–FW950.H2; OP940.00–OP940.a1; OP940.00–OP940.81

## Timeline

- 2026-08-15: disclosed: Initial publication of security bulletin
- 2026-08-19: patched: Fixed versions released: FW1120.01, FW1110.31, FW1060.81, FW950.H3, OP940.a2, OP940.82

## References

- [https://www.ibm.com/support/pages/node/7283236](https://www.ibm.com/support/pages/node/7283236)

## Related threats

- [IBM Power Systems firmware denial of service via input validation](https://junglewise.ai/threats/cve-2026-17427-ibm-power-systems-firmware-fw1060-00-through-fw1060-81-op940-00)
- [IBM Power Systems Firmware resource exhaustion DoS](https://junglewise.ai/threats/cve-2026-16678-ibm-power-systems-firmware-fw1110-00-through-fw1110-31-fw1120-00)
- [IBM Power Systems Firmware CSRF in ASMI web interface](https://junglewise.ai/threats/cve-2026-18848-ibm-power-systems-firmware-csrf-in-asmi-web-interface)
- [IBM Power Systems Firmware stack-based buffer overflow in BMC interface](https://junglewise.ai/threats/cve-2026-17494-ibm-power-systems-firmware-stack-based-buffer-overflow-in-bmc)
- [IBM Power Systems Firmware incorrect authorization in BMC/FSP interface](https://junglewise.ai/threats/cve-2026-17429-ibm-power-systems-firmware-incorrect-authorization-in-bmc-fsp)