Detect CVE-2026-48769 — Incus Arbitrary File Write via Trusted Image Hash in IBM QRadar
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
QRadar Detection Query
SELECT DATEFORMAT(devicetime, 'yyyy-MM-dd HH:mm:ss') AS event_time,
sourceip, username, "Process Name", "Command", "File Path"
FROM events
WHERE LOGSOURCETYPENAME(devicetype) IN ('Linux OS', 'Microsoft Windows Security Event Log', 'Syslog')
AND ("Process Name" ILIKE '%incus%' OR "Process Name" ILIKE '%incusd%')
AND (
"Command" ILIKE '%image copy%'
OR "Command" ILIKE '%image pull%'
OR "Command" ILIKE '%image import%'
OR "Command" ILIKE '%launch%'
)
AND "File Path" MATCHES '(?i)^(/etc/|/usr/bin/|/usr/sbin/|/bin/|/sbin/|/lib/|/root/|/home/).*'
LAST 24 HOURS
ORDER BY devicetime DESCIdentifies Incus processes performing image operations that result in file writes to sensitive host directories, which is anomalous behavior indicative of CVE-2026-48769 exploitation.
Data Sources
Required Tables
False Positives & Tuning
- Incus daemon writing container metadata or snapshots to paths under monitored directories
- Administrative scripts combining incus image commands with legitimate file management operations
- Storage backend integrations where incusd has elevated filesystem access for pool management
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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