Incus: Project restriction bypass leading to argument injection in mkfs
Summary
Incus, a system container and virtual machine manager, allows users of restricted projects to bypass the block.create_options restriction via volume update, copy and move operations. An attacker with low privileges who can create or edit custom volumes can inject arguments into the mkfs command, which runs as root, when the volume is copied or moved onto a pool that formats on copy. The attack requires a restricted project account and is mainly relevant for shared or multi-tenant Incus hosts.
Affected
- Incus 7.3.0 up to, but not including, 7.5.0
- Unconfirmed: 7.0.x LTS versions are mentioned in some third-party sources; vendor confirmation is pending
Fixed in
- Incus 7.5.0 or later
- Unconfirmed for 7.0.x LTS: ask the vendor or distributor before ruling it out
Workaround
- Do not grant custom volume creation to restricted projects on pools that format on copy
- Set volume.block.create_options on the pool so that the pool default applies
Exploitation
- No evidence of active exploitation found; not listed as known exploited in the sources checked
- No public proof of concept found; this does not rule one out
- CISA SSVC: exploitation none, automatable no, technical impact total
Our recommendation
- Inventory all Incus installations, including those run by third-party or managed services
- Upgrade affected installations to Incus 7.5.0 or later
- Until patched, restrict custom volume rights for restricted projects and check pool defaults for block.create_options
- Review restricted-project user accounts and access to the Incus API
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- GitHub Security Advisory GHSA-4cph-ccqv-hm3c github.com
- VulnCheck Advisory CVE-2026-115372 www.vulncheck.com
- Incus upstream fix pull request 4071 github.com
- Ubuntu security CVE-2026-115372 ubuntu.com
- Debian security bulletin BSA-139 backports.debian.org
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 31 Oct 2026, 08:04.
Original description (NVD)
Incus from 7.3.0 before 7.5.0 contains a project restriction bypass that allows restricted project users to set block.create_options through volume update, copy, and move operations. Attackers can set the option on a custom volume and trigger a copy or move onto a formatting pool to inject arguments into mkfs executed as root.
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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