Cyber Resilience

CVE-2026-16661

Memory Safety in Ibm Power System S1122 \(9824-22A\) Firmware fw1110.00 – fw1110.31

Published
19 August 2026
Modified
25 August 2026
Patch / advisory
CVSS Score v3.1 8.2
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
EPSS Score 0.0013 3th percentile
Risk Priority 52 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2026-16661 is a high-severity Integer Overflow or Wraparound (CWE-190) vulnerability in Ibm Power System S1122 \(9824-22A\) Firmware. Its CVSS base score is 8.2 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

IBM PowerVM Hypervisor FW1120.00, FW1110.00 through FW1110.30, FW1060.00 through FW1060.80, and FW950.00 through FW950.H2 is affected by a vulnerability in the service processor mailbox interface. An attacker with authenticated service-level access to the FSP can exploit this vulnerability, allowing arbitrary…

more

code to be executed in the host firmware runtime, giving full control over the managed system, resulting in a confidentiality, integrity, and availability impact to the managed system.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-17091Same product: Ibm Power System E1050 \(9043-Mrx\)
CVE-2026-16933Same product: Ibm Power System E1050 \(9043-Mrx\)
CVE-2026-17414Same product: Ibm Power System E1050 \(9043-Mrx\)
CVE-2026-17097Same product: Ibm Power System E1050 \(9043-Mrx\)
CVE-2026-16707Same product: Ibm Power System E1050 \(9043-Mrx\)
CVE-2026-17093Same product: Ibm Power System E1050 \(9043-Mrx\)
CVE-2026-18821Same product: Ibm Power System E1050 \(9043-Mrx\)
CVE-2026-17100Same product: Ibm Power System E1050 \(9043-Mrx\)
CVE-2026-11885Same product: Ibm Power System E1050 \(9043-Mrx\)
CVE-2026-19234Same product: Ibm Power System E1050 \(9043-Mrx\)

Affected Assets

ibm
power system s1122 \(9824-22a\) firmware
fw1120.00 · fw1110.00 — fw1110.31
ibm
power system s1124 \(9824-42a\) firmware
fw1120.00 · fw1110.00 — fw1110.31
ibm
power system s1122s \(9824-22b\) firmware
fw1120.00 · fw1110.00 — fw1110.31
ibm
power system s1114 \(9824-41b\) firmware
fw1120.00 · fw1110.00 — fw1110.31
ibm
power system l1122 \(9856-22h\) firmware
fw1120.00 · fw1110.00 — fw1110.31
ibm
power system l1124 \(9856-42h\) firmware
fw1120.00 · fw1110.00 — fw1110.31
ibm
power system e1150 \(9043-mru\) firmware
fw1120.00 · fw1110.00 — fw1110.31
ibm
power system s1112 \(9242-21b\) firmware
fw1120.00
ibm
power system s1112 \(9242-21t\) firmware
fw1120.00
ibm
power system e1080 \(9080-hex\) firmware
fw1060.00 — fw1060.81
+16 more product configuration(s) — see NVD for full list

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V5.2.6

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation (static analysis, fuzzing, unit tests) directly finds integer overflow defects before deployment.

Secure engineering principles require use of safe arithmetic constructs or language features that structurally eliminate integer overflow during calculation.

Input validation enforces bounds on values before arithmetic, stopping the conditions that trigger overflow or wraparound.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 partial match
prevents

Secure SDLC practices directly require use of safe arithmetic, bounds checks, and testing that prevent integer overflows.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Secure SDLC mandates input validation and arithmetic checks that prevent integer overflows.

degrades

Application security requirements include bounds checking and safe arithmetic to avoid overflow conditions.

degrades

Secure architecture principles require defensive coding patterns that mitigate integer wraparound risks.

prevents

Secure coding standards explicitly forbid unsafe integer operations and mandate overflow-safe constructs.

finds

Security testing in development can detect integer overflows before release.

References