Detect CVE-2026-48769 — Incus Arbitrary File Write via Trusted Image Hash in CrowdStrike LogScale
Detects exploitation of CVE-2026-48769, a critical arbitrary file write vulnerability in Incus (github.com/lxc/incus/v7/cmd/incusd) versions prior to 7.2.0. The flaw arises from improper validation (CWE-20) of image hashes during image pull operations, allowing a malicious or compromised image source to write arbitrary files on the Incus client host system. With a CVSS score of 9.9 and public PoC available, this vulnerability is actively exploitable and may lead to full host compromise, container escape, or persistence via overwritten system binaries or configuration files.
MITRE ATT&CK
LogScale Detection Query
event_simpleName IN (ProcessRollup2, SyntheticProcessRollup2)
| ImageFileName = /\/(incus|incusd)$/
| CommandLine = /(image\s+(copy|pull|import)|^incus\s+launch)/
| join
(
event_simpleName IN ("FileWritten", "PeFileWritten", "NewExecutableWritten")
| TargetFileName = /^(\/etc\/|\/usr\/bin\/|\/usr\/sbin\/|\/bin\/|\/sbin\/|\/lib\/|\/root\/|\/home\/)/
| ImageFileName = /\/(incus|incusd)$/
) by aid
| eval timedelta = abs(timestamp - join_timestamp)
| where timedelta <= 300000
| table timestamp, ComputerName, UserName, CommandLine, TargetFileName, timedelta
| sort -timestampCrowdStrike Falcon query identifying Incus image pull or launch commands followed by file write activity to sensitive host paths within 5 minutes on the same endpoint.
Data Sources
Required Tables
False Positives & Tuning
- CrowdStrike sensor noise during legitimate incus image cache management
- Container export/import workflows that temporarily stage files in monitored host directories
- Privileged CI runner environments where incusd operates with broad host filesystem access
Other platforms for CVE-2026-48769
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 1Simulate CVE-2026-48769 — Malicious Image Serving Arbitrary File Write
Expected signal: Process event: incus or incusd spawning with 'image copy' in command line; File creation event: /tmp/pwned created by incusd process; Network connection: incusd connecting to 127.0.0.1:18443
- Test 2Incus Version Detection and Vulnerable Host Discovery
Expected signal: Process events showing incus/incusd invoked with --version or version subcommand; curl process accessing /var/lib/incus/unix.socket
- Test 3Post-Exploitation — Persistence via Written Cron Job
Expected signal: Process event: process named incusd writing to /etc/cron.d/; File creation event: /etc/cron.d/incus-update created; auditd AVC or WRITE record for /etc/cron.d/
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