Raw vector
CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:NSummary
CVE-2026-23954 is a high-severity Path Traversal (CWE-22) vulnerability in Linuxcontainers Incus. Its CVSS base score is 8.7 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 49% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-23954 is a high-severity vulnerability (CVSS 8.7) affecting Incus, an open-source system container and virtual machine manager, in versions 6.21.0 and below. The issue stems from inadequate validation of source and target paths in the templating functionality when launching containers with custom images containing a metadata.yaml file with templates. This enables directory traversal (CWE-22) or symbolic link attacks, allowing arbitrary file reads and writes on the host system. The vulnerability also impacts IncusOS deployments.
An attacker requires low privileges, such as membership in the 'incus' group, granting the ability to launch containers with custom images. From this position, exploitation involves crafting malicious templates in the image's metadata.yaml to traverse directories or follow symlinks outside the container's namespace. Successful attacks yield arbitrary host file read/write access, escalating to full arbitrary command execution on the host with elevated privileges.
The Incus security advisory (GHSA-7f67-crqm-jgh7) details the root causes in specific code paths (e.g., driver_lxc.go lines 7215 and 7294), includes a proof-of-concept exploit script (template_arbitrary_write.sh), and provides a proposed patch (templates_arbitrary_write.patch). A fix is planned for Incus versions 6.0.6 and 6.21.0, but these had not been released as of the CVE publication on 2026-01-22. Security practitioners should restrict custom image launches and monitor for updates.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-3803
Vulnerability Data
Incus is a system container and virtual machine manager. Versions 6.21.0 and below allow a user with the ability to launch a container with a custom image (e.g a member of the ‘incus’ group) to use directory traversal or symbolic…
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links in the templating functionality to achieve host arbitrary file read, and host arbitrary file write. This ultimately results in arbitrary command execution on the host. When using an image with a metadata.yaml containing templates, both the source and target paths are not checked for symbolic links or directory traversal. This can also be exploited in IncusOS. A fix is planned for versions 6.0.6 and 6.21.0, but they have not been released at the time of publication.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V5.3.2
Mitigating Controls (NIST 800-53 r5) AI
Enforces the intended directory access authorizations that path traversal would otherwise bypass.
Input validation directly neutralizes special path elements before pathname construction occurs.
Least privilege reduces the impact of any unauthorized file access obtained via traversal.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Patching/maintenance can remediate known path-traversal flaws in deployed software (partial prevention of exploitability) but does nothing to stop the coding defect from being introduced in the first place.
PR.AA-05 defines and reviews access policies but does not address code-level pathname neutralization, so neither direction prevents CWE-22.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development catches path traversal via static/dynamic analysis.
Secure SDLC mandates input validation and path sanitization that directly prevent path traversal.
Application security requirements include rules for safe file handling and canonicalization.
Secure architecture principles require least-privilege file access and directory isolation.
Secure coding standards explicitly forbid unsafe path construction and mandate safe APIs.
Information access restriction limits which files an application may read or write.