CVE-2026-48681 Overview
CVE-2026-48681 is a directory traversal vulnerability [CWE-23] affecting OpenStack Ironic before version 35.0.2. The flaw allows file overwrite during bare-metal deployment when Ironic processes a crafted ISO image. An attacker with privileged access to supply deployment images can leverage path traversal sequences to write files outside the intended extraction directory. The vulnerability impacts the integrity and confidentiality of the deployment host while requiring high attack complexity and high privileges to exploit.
Critical Impact
A crafted ISO image processed during OpenStack Ironic deployment can overwrite arbitrary files on the host, enabling tampering with system binaries or configuration data.
Affected Products
- OpenStack Ironic versions prior to 35.0.2
- OpenStack deployments using Ironic bare-metal provisioning service
- Cloud infrastructure environments relying on Ironic ISO-based deployment workflows
Discovery Timeline
- 2026-06-04 - CVE-2026-48681 published to NVD
- 2026-06-04 - Last updated in NVD database
Technical Details for CVE-2026-48681
Vulnerability Analysis
The vulnerability resides in OpenStack Ironic's handling of ISO images during the bare-metal deployment workflow. Ironic mounts and extracts contents from deployment ISOs to stage files for provisioning target nodes. The extraction routine fails to validate file paths within the ISO, allowing entries with traversal sequences such as ../ to resolve outside the intended target directory. An attacker who can supply or modify a deployment ISO can craft entries that write to arbitrary locations on the Ironic conductor host.
File overwrite primitives on a deployment service host carry high impact. Overwriting binaries, systemd unit files, or configuration in paths like /etc or /usr/local/bin can lead to persistence, privilege escalation, or compromise of subsequent bare-metal deployments. Because Ironic typically runs with elevated privileges to perform deployment tasks, the impacted files can include sensitive system resources.
Root Cause
The root cause is improper limitation of a pathname to a restricted directory [CWE-23] during ISO image processing. Ironic does not normalize or canonicalize archive member paths before writing them to disk, allowing parent-directory traversal sequences to escape the extraction root.
Attack Vector
Exploitation requires an attacker with high privileges on the OpenStack environment who can submit a malicious ISO for use during deployment. The vector is classified as network-based because Ironic accepts deployment images over the network. No user interaction is required once the crafted ISO is queued for deployment. The high attack complexity reflects the conditions needed to control the deployment image and trigger processing on the conductor.
No public proof-of-concept code is available. See the Launchpad Bug Report and the Openwall OSS Security Discussion for technical context.
Detection Methods for CVE-2026-48681
Indicators of Compromise
- Unexpected files appearing outside Ironic's deployment staging directory on the conductor host
- Modifications to system binaries, init scripts, or configuration files coinciding with Ironic deployment events
- ISO images submitted to Ironic containing entries with ../ path traversal sequences
Detection Strategies
- Audit Ironic conductor logs for deployment operations involving ISO images from unverified sources
- Inspect ISO image contents for path traversal sequences before allowing them into deployment workflows
- Monitor file integrity on Ironic conductor hosts, particularly in directories outside the configured deployment workspace
Monitoring Recommendations
- Enable file integrity monitoring on /etc, /usr/bin, /usr/local, and Ironic service directories
- Forward Ironic API and conductor logs to a centralized logging platform for correlation with file modification events
- Alert on creation of files by the Ironic service account outside its expected working directories
How to Mitigate CVE-2026-48681
Immediate Actions Required
- Upgrade OpenStack Ironic to version 35.0.2 or later
- Restrict who can upload or register deployment ISO images in the OpenStack environment
- Audit existing deployment ISO images and source repositories for trustworthiness
- Review Ironic conductor hosts for unexpected file modifications since the vulnerable version was deployed
Patch Information
The issue is resolved in OpenStack Ironic version 35.0.2. Operators should upgrade conductor and API services to the patched release. Refer to the Launchpad Bug Report for upstream remediation details and the Openwall OSS Security Discussion for the coordinated disclosure thread.
Workarounds
- Limit privileges required to submit deployment images to a minimal set of trusted operators
- Validate ISO image contents for path traversal sequences before allowing Ironic to process them
- Run Ironic conductor services with the least privilege necessary and isolate the deployment workspace using mandatory access controls such as SELinux or AppArmor
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
