Detect CVE-2026-48751: Incus Restricted Project Bypass Leading to Arbitrary Command Execution in Google Chronicle
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
YARA-L Detection Query
rule cve_2026_48751_incus_restricted_bypass {
meta:
author = "Argus Detection Platform"
description = "Detects CVE-2026-48751 Incus restricted project bypass exploitation"
severity = "CRITICAL"
confidence = "MEDIUM"
mitre_attack_tactic = "Privilege Escalation, Execution"
cve = "CVE-2026-48751"
events:
$proc.metadata.event_type = "PROCESS_LAUNCH"
$proc.principal.process.file.full_path = /incusd|incus/
(
$proc.target.process.file.full_path = /\/(sh|bash|zsh|python3?|perl|ruby)$/
or
$proc.target.process.command_line = /nsenter|unshare|chroot|pivot_root/
)
condition:
$proc
}Chronicle YARA-L rule detecting shell processes or namespace manipulation commands spawned by incusd, indicating restricted project bypass exploitation per CVE-2026-48751.
Data Sources
Required Tables
False Positives & Tuning
- Legitimate incus exec operations by authorized system administrators
- Infrastructure automation using incus as a container runtime
- DevOps workflows with regular container exec operations
- Security tooling that uses incus exec for audit or compliance checks
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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