CVE-2026-107174 in OpenShift Container Platform
Summary
by MITRE • 10/07/2026
A flaw was found in source-to-image. When unpacking archive files, the application fails to properly sanitize symbolic links pointing to absolute file paths. An attacker who supplies a malicious builder image can exploit this vulnerability by embedding links pointing outside the extraction directory. This allows the attacker to bypass sandbox boundaries, potentially leading to unauthorized information disclosure or file modification on the host system.
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Analysis
by VulDB Data Team • 10/07/2026
The source-to-image tool is designed to build container images from application sources using Dockerfiles embedded within those sources. A critical security flaw exists in how this utility handles archive files during the extraction process. Specifically, when unpacking archives such as tarballs, the application fails to adequately sanitize symbolic links that point to absolute file paths rather than relative ones within the intended directory structure. This oversight creates a significant path traversal vulnerability where an attacker can manipulate the filesystem layout of the extracted content. By embedding symbolic links in a malicious builder image that reference locations outside the designated extraction sandbox boundary, an adversary can effectively escape the isolated environment intended for building images.
This technical flaw allows for unauthorized access to files and directories on the host system or within other containers sharing the same file system namespace. The operational impact is severe because it bypasses the security boundaries established by containerization technologies like Docker or Podman. An attacker who controls a malicious builder image can exploit this weakness to read sensitive configuration files, environment variables containing secrets, or source code from adjacent projects on the host machine. Furthermore, if write permissions are available in the targeted directories, the vulnerability could be leveraged for file modification, potentially leading to remote code execution or persistent compromise of the underlying infrastructure by overwriting critical system binaries or application configurations with malicious payloads.
From a classification perspective, this vulnerability aligns closely with CWE-22: Improper Limitation of a Pathname to a Restricted Directory, commonly known as path traversal. It also relates to CWE-78: Improper Neutralization of Special Elements used in an OS Command if the extracted files are subsequently executed or processed by other tools within the pipeline. In terms of adversary tactics, this exploit maps to MITRE ATT&CK technique T1046: Network Service Discovery for information gathering and potentially T1530: Data from Cloud Storage Object if cloud-based artifacts are accessed via the escaped paths. The core issue lies in the lack of strict validation on symbolic link targets during the archive extraction phase, which is a fundamental requirement for secure file handling in container build contexts.
Mitigation strategies must focus on both immediate remediation and long-term architectural improvements. Users should immediately update source-to-image to the latest patched version where this sanitization logic has been corrected to reject or safely resolve absolute symbolic links within extracted archives. In environments where updating is not instantly feasible, administrators can implement strict network policies to limit outbound connections from build containers and restrict file system permissions so that even if an escape occurs, the attacker cannot write to critical host directories. Additionally, adopting a policy of least privilege for containerized builds ensures that no single compromised builder image has excessive access rights. Regular auditing of third-party images used in CI/CD pipelines is also recommended to detect any pre-existing malicious artifacts before they are processed by vulnerable tooling.