Detect CVE-2026-48769 — Incus Arbitrary File Write via Trusted Image Hash in Sumo Logic CSE
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
Sumo Detection Query
_sourceCategory=endpoint/linux OR _sourceCategory=endpoint/sysmon
| where process_name matches /incus(d)?/
| where command matches /image (copy|pull|import)|launch/
| timeslice 5m
| join
(
_sourceCategory=endpoint/linux OR _sourceCategory=endpoint/sysmon
| where process_name matches /incus(d)?/
| where file_path matches /^\/etc\/|\/usr\/bin\/|\/usr\/sbin\/|\/bin\/|\/sbin\/|\/lib\/|\/root\/|\/home\//
| where event_type in ("file_create", "file_modify", "file_write")
) on host
| fields _time, host, user, command, file_path
| sort by _time descSumo Logic query detecting Incus image pull or launch commands correlated with suspicious file write events on sensitive host directories.
Data Sources
Required Tables
False Positives & Tuning
- Incus writing to /var/lib/incus or /run/incus which may be under monitored parent paths
- Container migration or export operations that interact with host file paths
- Automated deployment pipelines using incus image operations with broad permissions
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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