CVE-2026-41648 Incus: Unbounded YAML Metadata Decode via Parsing
An authenticated user can cause a denial of service by uploading a crafted image or backup tarball with unbounded YAML metadata.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-41648?
CVE-2026-41648 is a medium-severity denial of service vulnerability in lxc incus, published on 7 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Incus is a system container and virtual machine manager. Prior to version 7.0.0, user provided image and backup tarballs would be unpacked and YAML files parsed without any size restrictions. This was making it easy for an authenticated user to provide a crafted image or backup tarball that when parsed by Incus would lead to a very large YAML document being loaded into memory, potentially causing the entire server to run out of memory. This issue has been patched in version 7.0.0.
Weakness: CWE-770
Which versions are affected by CVE-2026-41648?
4 open source packages ship an affected version, including github.com/lxc/incus/v6/cmd/incusd, github.com/lxc/incus and github.com/lxc/incus/v6. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/lxc/incus/v6/cmd/incusd Go | All versions to 6.23.0 | None |
github.com/lxc/incus/v6/cmd/incusd Go | All versions to 6.23.0 | None |
github.com/lxc/incus Go | All versions | None |
github.com/lxc/incus/v6 Go | All versions | None |
Products include Linuxcontainers Incus.
How do I fix CVE-2026-41648?
Upgrade to a fixed version.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-41648 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-41648 exists.
Other vulnerabilities in lxc incus
- CVE-2026-33897 Incus vulnerable to arbitrary file read and write through pongo templates
- CVE-2026-33945 Abitrary file write through systemd-creds option
- CVE-2026-33898 Local Incus UI web server vulnerable to nuthentication bypass
- CVE-2026-23953 Incus container environment configuration newline injection
- CVE-2026-23954 Incus container image templating arbitrary host file read and write
Sources
Also known as DEBIAN-CVE-2026-41648, GHSA-67wx-r9xr-x75x, GO-2026-5168, UBUNTU-CVE-2026-41648.