8.2
HIGH CVSS 3.1
CVE-2026-16661
Power System Integer Overflow
Description

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 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.

INFO

Published Date :

Aug. 19, 2026, 8:17 p.m.

Last Modified :

Aug. 25, 2026, 7:35 p.m.

Remotely Exploit :

No
Affected Products

The following products are affected by CVE-2026-16661 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Ibm powervm_hypervisor
2 Ibm powervm_hypervisor
3 Ibm power_system_e1080_\(9080-hex\)_firmware
4 Ibm power_system_e1080_\(9080-hex\)
5 Ibm power_system_s922_\(9009-22g\)_firmware
6 Ibm power_system_s922_\(9009-22g\)
7 Ibm power_system_h922_\(9223-22s\)_firmware
8 Ibm power_system_h922_\(9223-22s\)
9 Ibm power_system_s914_\(9009-41g\)_firmware
10 Ibm power_system_s914_\(9009-41g\)
11 Ibm power_system_s924_\(9009-42g\)_firmware
12 Ibm power_system_s924_\(9009-42g\)
13 Ibm power_system_h924_\(9223-42s\)_firmware
14 Ibm power_system_h924_\(9223-42s\)
15 Ibm power_system_e950_\(9040-mr9\)_firmware
16 Ibm power_system_e950_\(9040-mr9\)
17 Ibm power_system_e980_\(9080-m9s\)_firmware
18 Ibm power_system_e980_\(9080-m9s\)
19 Ibm power_system_e1050_\(9043-mrx\)
20 Ibm power_system_l1022_\(9786-22h\)
21 Ibm power_system_l1024_\(9786-42h\)
22 Ibm power_system_s1012_\(9028-21b\)
23 Ibm power_system_s1014_\(9105-41b\)
24 Ibm power_system_s1022_\(9105-22a\)
25 Ibm power_system_s1022s_\(9105-22b\)
26 Ibm power_system_s1024_\(9105-42a\)
27 Ibm power_system_e1180_\(9080-heu\)_firmware
28 Ibm power_system_e1180_\(9080-heu\)
29 Ibm power_system_s1122_\(9824-22a\)_firmware
30 Ibm power_system_s1122_\(9824-22a\)
31 Ibm power_system_s1124_\(9824-42a\)_firmware
32 Ibm power_system_s1124_\(9824-42a\)
33 Ibm power_system_s1122s_\(9824-22b\)_firmware
34 Ibm power_system_s1122s_\(9824-22b\)
35 Ibm power_system_s1114_\(9824-41b\)_firmware
36 Ibm power_system_s1114_\(9824-41b\)
37 Ibm power_system_l1122_\(9856-22h\)_firmware
38 Ibm power_system_l1122_\(9856-22h\)
39 Ibm power_system_l1124_\(9856-42h\)_firmware
40 Ibm power_system_l1124_\(9856-42h\)
41 Ibm power_system_e1150_\(9043-mru\)_firmware
42 Ibm power_system_e1150_\(9043-mru\)
43 Ibm power_system_s1112_\(9242-21b\)_firmware
44 Ibm power_system_s1112_\(9242-21b\)
45 Ibm power_system_s1112_\(9242-21t\)_firmware
46 Ibm power_system_s1112_\(9242-21t\)
47 Ibm power_system_s1022_\(9105-22a\)_firmware
48 Ibm power_system_s1024_\(9105-42a\)_firmware
49 Ibm power_system_s1022s_\(9105-22b\)_firmware
50 Ibm power_system_s1014_\(9105-41b\)_firmware
51 Ibm power_system_l1022_\(9786-22h\)_firmware
52 Ibm power_system_l1024_\(9786-42h\)_firmware
53 Ibm power_system_e1050_\(9043-mrx\)_firmware
54 Ibm power_system_s1012_\(9028-21b\)_firmware
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 HIGH 9a959283-ebb5-44b6-b705-dcc2bbced522
CVSS 3.1 HIGH [email protected]
CVSS 3.1 HIGH MITRE-CVE
Solution
Apply firmware updates to address arbitrary code execution in the service processor.
  • Update IBM PowerVM Hypervisor firmware to the latest version.
  • Consult IBM documentation for specific update procedures.
  • Verify successful firmware installation.
  • Restrict service processor access.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-16661.

URL Resource
https://www.ibm.com/support/pages/node/7283237 Vendor Advisory
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-16661 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-16661 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-16661 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-16661 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • Initial Analysis by [email protected]

    Aug. 25, 2026

    Action Type Old Value New Value
    Added CPE Configuration AND OR *cpe:2.3:o:ibm:power_system_s1122_(9824-22a)_firmware:*:*:*:*:*:*:*:* versions from (including) fw1110.00 up to (excluding) fw1110.31 *cpe:2.3:o:ibm:power_system_s1122_(9824-22a)_firmware:fw1120.00:*:*:*:*:*:*:* OR cpe:2.3:h:ibm:power_system_s1122_(9824-22a):-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:ibm:power_system_s1124_(9824-42a)_firmware:*:*:*:*:*:*:*:* versions from (including) fw1110.00 up to (excluding) fw1110.31 *cpe:2.3:o:ibm:power_system_s1124_(9824-42a)_firmware:fw1120.00:*:*:*:*:*:*:* OR cpe:2.3:h:ibm:power_system_s1124_(9824-42a):-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:ibm:power_system_s1122s_(9824-22b)_firmware:*:*:*:*:*:*:*:* versions from (including) fw1110.00 up to (excluding) fw1110.31 *cpe:2.3:o:ibm:power_system_s1122s_(9824-22b)_firmware:fw1120.00:*:*:*:*:*:*:* OR cpe:2.3:h:ibm:power_system_s1122s_(9824-22b):-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:ibm:power_system_s1114_(9824-41b)_firmware:*:*:*:*:*:*:*:* versions from (including) fw1110.00 up to (excluding) fw1110.31 *cpe:2.3:o:ibm:power_system_s1114_(9824-41b)_firmware:fw1120.00:*:*:*:*:*:*:* OR cpe:2.3:h:ibm:power_system_s1114_(9824-41b):-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:ibm:power_system_l1122_(9856-22h)_firmware:*:*:*:*:*:*:*:* versions from (including) fw1110.00 up to (excluding) fw1110.31 *cpe:2.3:o:ibm:power_system_l1122_(9856-22h)_firmware:fw1120.00:*:*:*:*:*:*:* OR cpe:2.3:h:ibm:power_system_l1122_(9856-22h):-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:ibm:power_system_l1124_(9856-42h)_firmware:*:*:*:*:*:*:*:* versions from (including) fw1110.00 up to (excluding) fw1110.31 *cpe:2.3:o:ibm:power_system_l1124_(9856-42h)_firmware:fw1120.00:*:*:*:*:*:*:* OR cpe:2.3:h:ibm:power_system_l1124_(9856-42h):-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:ibm:power_system_e1150_(9043-mru)_firmware:*:*:*:*:*:*:*:* versions from (including) fw1110.00 up to (excluding) fw1110.31 *cpe:2.3:o:ibm:power_system_e1150_(9043-mru)_firmware:fw1120.00:*:*:*:*:*:*:* OR cpe:2.3:h:ibm:power_system_e1150_(9043-mru):-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:ibm:power_system_s1112_(9242-21b)_firmware:fw1120.00:*:*:*:*:*:*:* OR cpe:2.3:h:ibm:power_system_s1112_(9242-21b):-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:ibm:power_system_s1112_(9242-21t)_firmware:fw1120.00:*:*:*:*:*:*:* OR cpe:2.3:h:ibm:power_system_s1112_(9242-21t):-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:ibm:power_system_e1080_(9080-hex)_firmware:*:*:*:*:*:*:*:* versions from (including) fw1060.00 up to (excluding) fw1060.81 OR cpe:2.3:h:ibm:power_system_e1080_(9080-hex):-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:ibm:power_system_s1022_(9105-22a)_firmware:*:*:*:*:*:*:*:* versions from (including) fw1060.00 up to (excluding) fw1060.81 OR cpe:2.3:h:ibm:power_system_s1022_(9105-22a):-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:ibm:power_system_s1024_(9105-42a)_firmware:*:*:*:*:*:*:*:* versions from (including) fw1060.00 up to (excluding) fw1060.81 OR cpe:2.3:h:ibm:power_system_s1024_(9105-42a):-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:ibm:power_system_s1022s_(9105-22b)_firmware:*:*:*:*:*:*:*:* versions from (including) fw1060.00 up to (excluding) fw1060.81 OR cpe:2.3:h:ibm:power_system_s1022s_(9105-22b):-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:ibm:power_system_s1014_(9105-41b)_firmware:*:*:*:*:*:*:*:* versions from (including) fw1060.00 up to (excluding) fw1060.81 OR cpe:2.3:h:ibm:power_system_s1014_(9105-41b):-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:ibm:power_system_l1022_(9786-22h)_firmware:*:*:*:*:*:*:*:* versions from (including) fw1060.00 up to (excluding) fw1060.81 OR cpe:2.3:h:ibm:power_system_l1022_(9786-22h):-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:ibm:power_system_l1024_(9786-42h)_firmware:*:*:*:*:*:*:*:* versions from (including) fw1060.00 up to (excluding) fw1060.81 OR cpe:2.3:h:ibm:power_system_l1024_(9786-42h):-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:ibm:power_system_e1050_(9043-mrx)_firmware:*:*:*:*:*:*:*:* versions from (including) fw1060.00 up to (excluding) fw1060.81 OR cpe:2.3:h:ibm:power_system_e1050_(9043-mrx):-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:ibm:power_system_s1012_(9028-21b)_firmware:*:*:*:*:*:*:*:* versions from (including) fw1060.00 up to (excluding) fw1060.81 OR cpe:2.3:h:ibm:power_system_s1012_(9028-21b):-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:ibm:power_system_e1180_(9080-heu)_firmware:*:*:*:*:*:*:*:* versions from (including) fw1110.00 up to (excluding) fw1110.31 *cpe:2.3:o:ibm:power_system_e1180_(9080-heu)_firmware:fw1120.00:*:*:*:*:*:*:* OR cpe:2.3:h:ibm:power_system_e1180_(9080-heu):-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:ibm:power_system_s922_(9009-22g)_firmware:*:*:*:*:*:*:*:* versions from (including) fw950.00 up to (excluding) fw950.h3 OR cpe:2.3:h:ibm:power_system_s922_(9009-22g):-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:ibm:power_system_h922_(9223-22s)_firmware:*:*:*:*:*:*:*:* versions from (including) fw950.00 up to (excluding) fw950.h3 OR cpe:2.3:h:ibm:power_system_h922_(9223-22s):-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:ibm:power_system_s914_(9009-41g)_firmware:*:*:*:*:*:*:*:* versions from (including) fw950.00 up to (excluding) fw950.h3 OR cpe:2.3:h:ibm:power_system_s914_(9009-41g):-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:ibm:power_system_s924_(9009-42g)_firmware:*:*:*:*:*:*:*:* versions from (including) fw950.00 up to (excluding) fw950.h3 OR cpe:2.3:h:ibm:power_system_s924_(9009-42g):-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:ibm:power_system_h924_(9223-42s)_firmware:*:*:*:*:*:*:*:* versions from (including) fw950.00 up to (excluding) fw950.h3 OR cpe:2.3:h:ibm:power_system_h924_(9223-42s):-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:ibm:power_system_e950_(9040-mr9)_firmware:*:*:*:*:*:*:*:* versions from (including) fw950.00 up to (excluding) fw950.h3 OR cpe:2.3:h:ibm:power_system_e950_(9040-mr9):-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:ibm:power_system_e980_(9080-m9s)_firmware:*:*:*:*:*:*:*:* versions from (including) fw950.00 up to (excluding) fw950.h3 OR cpe:2.3:h:ibm:power_system_e980_(9080-m9s):-:*:*:*:*:*:*:*
    Added Reference Type IBM Corporation: https://www.ibm.com/support/pages/node/7283237 Types: Vendor Advisory
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Aug. 22, 2026

    Action Type Old Value New Value
    Changed SSVC {'id': 'CVE-2026-16661', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-21T16:09:05.671804Z'} {'id': 'CVE-2026-16661', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-21T00:00:00+00:00'}
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Aug. 21, 2026

    Action Type Old Value New Value
    Added SSVC {'id': 'CVE-2026-16661', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-21T16:09:05.671804Z'}
  • New CVE Received by [email protected]

    Aug. 19, 2026

    Action Type Old Value New Value
    Added Affected [{'cpes': ['cpe:2.3:o:ibm:power_systems_firmware:fw1120.00:*:*:*:*:*:*:*', 'cpe:2.3:o:ibm:power_systems_firmware:fw1110.00:*:*:*:*:*:*:*', 'cpe:2.3:o:ibm:power_systems_firmware:fw1110.30:*:*:*:*:*:*:*', 'cpe:2.3:o:ibm:power_systems_firmware:fw1060.00:*:*:*:*:*:*:*', 'cpe:2.3:o:ibm:power_systems_firmware:fw1060.80:*:*:*:*:*:*:*', 'cpe:2.3:o:ibm:power_systems_firmware:fw950.00:*:*:*:*:*:*:*', 'cpe:2.3:o:ibm:power_systems_firmware:fw950.h2:*:*:*:*:*:*:*'], 'vendor': 'IBM', 'product': 'PowerVM Hypervisor', 'versions': [{'status': 'affected', 'version': 'FW1120.00'}, {'status': 'affected', 'version': 'FW1110.00', 'versionType': 'semver', 'lessThanOrEqual': 'FW1110.30'}, {'status': 'affected', 'version': 'FW1060.00', 'versionType': 'semver', 'lessThanOrEqual': 'FW1060.80'}, {'status': 'affected', 'version': 'FW950.00', 'versionType': 'semver', 'lessThanOrEqual': 'FW950.H2'}]}]
    Added Description 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 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.
    Added CVSS V3.1 AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
    Added CWE CWE-190
    Added Reference https://www.ibm.com/support/pages/node/7283237
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.