Security Digest · Vulnerability record
CVE-2026-48749: Incus has an arbitrary file read+write on host via rootfs/ symlink in malicious image
Incus is a system container and virtual machine manager.
CVSS 9.9 Critical EPSS 0.7% · p54
Should you act?
Critical, preconditions apply
Severe if exploited, but exploitation needs conditions that may not apply to you. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.
- Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.7%, percentile 54: FIRST’s model estimates a 0.7% chance of exploitation activity in the next 30 days, higher than 54% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Needs an account (low (any account)). Exposure depends on who can log in.
- Only applies if your dependency tree includes
github.com/lxc/incus/v7/cmd/incusd(Go) < 7.2.0, fixed in 7.2.0. Check your lockfile, including transitive dependencies.
What it is
Incus is a system container and virtual machine manager. Prior to version 7.2.0, a specially crafted image can be used to read or create/write arbitrary files on the host; possibly leading to arbitrary command execution. Version 7.2.0 fixes the issue.
From the GitHub advisory
Summary
A specially crafted image can be used to read or create/write arbitrary files on the host; possibly leading to arbitrary command execution.
Details
Incus validates an image as soon as it sees a normal metadata.yaml and a rootfs/ entry, but full extraction can later process a duplicate top-level rootfs symlink. Later, the stopped-container file API opens d.RootfsPath() and passes that file descriptor to forkfile, which chroots to it.
In practice, this allows a malicious actor to access the host's filesystem with root privileges.
Weakness type: CWE-73.
Product: github.com/lxc/incus/v7/cmd/incusd (Go) · Assigned by: GitHub_M · Published: 2026-08-21
Affected and fixed versions
| Ecosystem | Package | Vulnerable | First fixed |
|---|---|---|---|
| Go | github.com/lxc/incus/v7/cmd/incusd | < 7.2.0 | 7.2.0 |
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| lxc | incus | < 7.2.0 |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_M | 3.1 | 9.9 Critical | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
| GitHub | 3.1 | 9.9 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
- Attack vector: network (remotely reachable)
- Attack complexity: low
- Privileges required: low (any account)
- User interaction: none
- Scope: changed (can affect other components)
CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.
Exploitation and urgency
- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc, automatable no, technical impact total.
- FIRST EPSS (model of 2026-10-21): 0.73% probability of exploitation activity in the next 30 days; percentile 54.
Timeline
- — GitHub-reviewed advisory GHSA-2q3f-q5pq-g8wv published (critical)
- — CVE record last updated
- — CVE record published by GitHub_M
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vulnerability records
- GitHub Advisory GHSA-2q3f-q5pq-g8wv github.com
- CVE.org record CVE-2026-48749 cve.org
- NVD entry CVE-2026-48749 nvd.nist.gov
Other references from the CVE record and advisory
- github.com github.com