CVE-2026-18821
Power System Out-of-bounds Write
Description
IBM PowerVM Hypervisor FW1120.00, FW1110.00 through FW1110.30, FW1060.00 through FW1060.80, and FW950.00 through FW950.H2 Power Systems Firmware is affected by a vulnerability in partition firmware during network boot. An unauthenticated attacker on the same network as a partition undergoing network boot can send a malformed packet, allowing arbitrary code to be executed in the partition firmware and compromising everything subsequently loaded by that partition. Other partitions and the managed system are not affected. Only partitions actively performing a network boot are affected, resulting in a confidentiality, integrity, and availability impact.
INFO
Published Date :
Aug. 19, 2026, 8:17 p.m.
Last Modified :
Aug. 19, 2026, 8:17 p.m.
Remotely Exploit :
No
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-18821
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.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 9a959283-ebb5-44b6-b705-dcc2bbced522 | ||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update firmware to a version addressing this vulnerability.
- Consult IBM documentation for specific update instructions.
- Ensure network boot process is secured.
- Monitor network traffic for anomalies.
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-2026-18821.
| URL | Resource |
|---|---|
| https://www.ibm.com/support/pages/node/7283232 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-18821 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-2026-18821
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-2026-18821 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-18821 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.
-
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 Power Systems Firmware is affected by a vulnerability in partition firmware during network boot. An unauthenticated attacker on the same network as a partition undergoing network boot can send a malformed packet, allowing arbitrary code to be executed in the partition firmware and compromising everything subsequently loaded by that partition. Other partitions and the managed system are not affected. Only partitions actively performing a network boot are affected, resulting in a confidentiality, integrity, and availability impact. Added CVSS V3.1 AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Added CWE CWE-787 Added Reference https://www.ibm.com/support/pages/node/7283232