CVE-2026-43003

High

Published: 01 May 2026

Published

01 May 2026

Modified

04 May 2026

KEV Added

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Patch

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CVSS Score 8.0 CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

EPSS Score 0.0004 11.6th percentile

Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-43003 is a high-severity Inclusion of Functionality from Untrusted Control Sphere (CWE-829) vulnerability in Openstack Ironic Python Agent. Its CVSS base score is 8.0 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation of Remote Services (T1210); ranked at the 11.6th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 SC-35 (External Malicious Code Identification) and SI-3 (Malicious Code Protection).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploitation of Remote Services (T1210). What defenders deploy: see the NIST 800-53 controls recommended below.

Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

SI-3 Malicious Code Protection good match

prevent

Employs malicious code protection mechanisms to scan and eradicate malicious payloads in untrusted partition images before executing grub-install within the chroot environment.

SC-35 External Malicious Code Identification good match

prevent

Identifies and blocks external malicious code contained in the deployed partition image prior to chroot execution during deployment.

SR-10 Inspection of Systems or Components good match

prevent

Requires inspection of untrusted partition images as supplied components to detect malicious functionality before processing with grub-install in chroot.

MITRE ATT&CK Enterprise TechniquesAI

T1210 Exploitation of Remote Services Lateral Movement

Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.

attack.mitre.org →

Why these techniques?

The vulnerability enables arbitrary code execution in the Ironic Python Agent (a remote provisioning service) when processing a malicious partition image, directly mapping to exploitation of remote services to execute adversary-controlled code.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

An issue was discovered in OpenStack ironic-python-agent 1.0.0 through 11.5.0. Ironic Python Agent (IPA) sometimes executes grub-install from within a chroot of the deployed partition image, leading to code execution in the case of a malicious image.

Deeper analysisAI

CVE-2026-43003 is a vulnerability in OpenStack's Ironic Python Agent (IPA) affecting versions 1.0.0 through 11.5.0. The issue arises when IPA executes the grub-install command from within a chroot environment of a deployed partition image, which can lead to arbitrary code execution if the image is malicious. This flaw is classified under CWE-829 (Inclusion of Functionality from Untrusted Control Sphere) and carries a CVSS v3.1 base score of 8.0 (AV:A/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H), indicating high severity due to its potential for significant confidentiality, integrity, and availability impacts with a changed scope.

An attacker with low privileges (PR:L) on an adjacent network (AV:A) could exploit this vulnerability, though it requires high attack complexity (AC:H) and no user interaction (UI:N). Exploitation occurs when IPA processes a malicious partition image during deployment, allowing the attacker to achieve code execution within the agent's context. Successful exploitation grants high-level access to confidential data, modification of system integrity, and disruption of availability across the scoped components.

Advisories reference the issue in Launchpad bug 2148310 and a specific code snippet in ironic-python-agent's efi_utils.py (lines 134-139 in commit 236b33abffe6688afc39c21e351cc3889b3db2dd), highlighting the problematic grub-install execution. Practitioners should review these for patch details and upgrade to remediated versions beyond 11.5.0.