Detect CVE-2026-48751: Incus Restricted Project Bypass Leading to Arbitrary Command Execution in Elastic Security
Detects exploitation of CVE-2026-48751, a critical missing authorization vulnerability (CWE-862) in Incus (github.com/lxc/incus/v7/cmd/incusd) versions prior to 7.2.0. An attacker with access to a restricted Incus project can bypass project restrictions to execute arbitrary commands on the host system, achieving container escape with a CVSS score of 9.9. A public proof-of-concept is available.
MITRE ATT&CK
Elastic Detection Query
sequence by host.name with maxspan=2m
[process where event.type == "start"
and process.parent.name in ("incusd", "incus")
and process.name in ("sh", "bash", "zsh", "python3", "python", "perl", "ruby")]
[process where event.type == "start"
and process.args : ("nsenter", "unshare", "chroot", "pivot_root", "--target", "--mount", "--pid", "--net")
and process.parent.name in ("sh", "bash", "zsh", "python3", "python", "perl", "ruby")]EQL sequence rule detecting shell spawn from incusd followed by namespace manipulation commands within 2 minutes, indicating a container escape attempt via CVE-2026-48751.
Data Sources
Required Tables
False Positives & Tuning
- Legitimate incus exec workflows that include namespace inspection for debugging
- Security tooling that uses namespace inspection as part of container auditing
- Automated build pipelines running inside Incus containers with exec-heavy workloads
Other platforms for CVE-2026-48751
Testing Methodology
Validate this detection against 3 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1Incus Restricted Project Shell Escape via Exec API
Expected signal: Process audit logs showing incusd spawning /bin/sh or nsenter with parent PID of incusd; auditd EXECVE records for nsenter or chroot with ppid matching incusd; /proc/<pid>/ns/pid symlink pointing to host PID namespace
- Test 2Verify Incus Vulnerable Version Present
Expected signal: Process execution events for incusd --version and incus project list; API calls to /1.0/projects and /1.0/instances visible in incusd access logs
- Test 3Container Escape via Host Namespace Entry Post-Bypass
Expected signal: Auditd SYSCALL records for nsenter (execve), unshare, clone syscalls; /proc/<pid>/ns/pid and /proc/<pid>/ns/mnt symlinks showing target namespace 1 (host init); process tree showing sh/bash with host-level PID namespace confirmed by NSpid field in /proc/self/status
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