Description

Incus is a system container and virtual machine manager. Prior to version 7.2.0, a specially crafted image can be used to read or create/write arbitrary files on the host; possibly leading to arbitrary command execution. Version 7.2.0 fixes the issue.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "9.9",
  "pubDate": "2026-08-21T15:16:40.247Z",
  "pubdate": "2026-08-21T15:16:40.247Z",
  "executiveSummary": "An arbitrary file read and write vulnerability exists in Incus prior to version 7.2.0. The vulnerability allows a specially crafted image to facilitate unauthorized read, creation, and write operations targeting arbitrary files on the host system. This security flaw poses severe risk implications, potentially leading to arbitrary command execution on the underlying host. The attacker capability centers on the supply or utilization of a malicious system container or virtual machine image. Exploitation requirements involve processing the specially crafted image within the Incus management environment. The impact spans complete confidentiality and integrity compromise of the host filesystem, which can subsequently be leveraged by malicious actors to achieve full system compromise through persistent code execution or privilege escalation vectors.",
  "technicalDetails": "The vulnerability resides within the image handling and unpacking or processing components of Incus prior to version 7.2.0. The root cause stems from insufficient validation and sanitization of paths or structural elements within imported images, enabling directory traversal or improper file redirection during image extraction and instantiation phases. The affected component is responsible for parsing and deploying system container and virtual machine images. Exploitation occurs when an administrator or automated process imports and utilizes a specially crafted malicious image designed to exploit these parsing weaknesses. The attack flow begins with the malicious image containing specially manipulated internal file paths or symlinks. When Incus processes this image, it fails to adequately restrict file operations to the designated container or virtual machine rootfs boundaries. Consequently, writing or reading operations break out of the intended confinement sandbox and interact directly with the host filesystem. This mechanism allows an attacker to overwrite critical host configuration files, drop unauthorized binaries into system paths, or exfiltrate sensitive host data through arbitrary file read operations. Post-exploitation impact directly correlates with the specific files targeted; writing to system binaries or startup scripts routinely culminates in arbitrary command execution with the privileges of the Incus daemon or root user. The vulnerability affects Incus versions prior to 7.2.0. Network exposure and authentication requirements depend on the specific deployment configuration of the Incus API and remote image import workflows, though the core vulnerability is triggered during the processing phase of the untrusted image payload."
}