CVE-2026-16835: IBM Power Systems firmware authentication bypass in FSP management protocol

CVE-2026-16835 · Severity: critical · CVSS 9.6 · Published 2026-08-19

IBM Power Systems firmware contains a flaw in the FSP (Flexible Service Processor) management network protocol that allows an attacker on the management network to bypass authentication entirely. An unauthenticated attacker can seize complete administrative control of the managed system—power cycling partitions, altering system configuration, and accessing partition consoles—affecting confidentiality, integrity, and availability of hosted workloads. This is a severe threat to data center operations and security posture.

Technologies: IBM Power Systems Firmware. Vendors: IBM.

Quick answers

Is CVE-2026-16835 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-16835 being exploited in the wild.
How severe is CVE-2026-16835?
Critical severity, with a CVSS score of 9.6, published 19 August 2026.
Which products and versions are affected?
IBM Power Systems Firmware FW950.00 through FW950.H2, FW1060.00 through FW1060.80, FW1110.00 through FW1110.30, FW1120.00.
Is there a fix for CVE-2026-16835?
A patch was published on 2026-08: IBM released patches: FW1120.01, FW1110.31, FW1060.81, FW950.H3 or newer Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-16835 attacked?
It is attacked from the adjacent network, in device firmware.
Am I affected by CVE-2026-16835?
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 improper certificate validation issue (CWE-295) in the FSP management network protocol. An unauthenticated attacker positioned on the management network can bypass authentication checks and perform any administrative operation on the managed system, including power state control, system configuration modification, and console access across all partitions. Attack vector is adjacent (management network), requires no authentication or user interaction, and has scope change—allowing an attacker to move laterally or affect multiple partitions. Patches have been released: FW1120.01, FW1110.31, FW1060.81, and FW950.H3 or newer depending on platform generation.

Affected products

  • IBM Power Systems Firmware FW950.00 through FW950.H2, FW1060.00 through FW1060.80, FW1110.00 through FW1110.30, FW1120.00

Timeline

  • 2026-08-15: disclosed: Initial publication by IBM
  • 2026-08: patched: IBM released patches: FW1120.01, FW1110.31, FW1060.81, FW950.H3 or newer

References

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