Description
An improper sanitization of the compression_algorithm parameter in Canonical LXD allows an authenticated, unprivileged user to execute commands as the LXD daemon on the LXD server via API calls to the image and backup endpoints. This issue affected LXD from 4.12 through 6.6 and was fixed in the snap versions 5.0.6-e49d9f4 (channel 5.0/stable), 5.21.4-1374f39 (channel 5.21/stable), and 6.7-1f11451 (channel 6.0 stable). The channel 4.0/stable is not affected as it contains version 4.0.10.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Canonical | lxd | 6.0 – < 6.7, 5.21.0 – < 5.21.4, 5.0.0 – < 5.0.6, 4.12 | 6.7 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | incus | 6.0.6-1 | — |
| Debian 13 | incus | 6.0.4-2+deb13u5 | DSA-6184-1 |
| Debian 13 | lxd | 5.0.2+git20231211.1364ae4-9+deb13u4 | DSA-6188-1 |
| Debian 12 | lxd | 5.0.2-5+deb12u4 | DSA-6188-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | incus | 6.0.6-r0 | — |
| Alpine v3.23 | incus | 6.0.6-r0 | — |
Advisories 2
- DSA-6188-1 lxd - security update Debian Security (DSA / DLA) · Mar 31, 2026
- DSA-6184-1 incus - security update Debian Security (DSA / DLA) · Mar 29, 2026
References
- https://github.com/canonical/lxd/security/advisories/GHSA-4rmf-rcp8-2r9g vendor-advisory
- https://github.com/canonical/lxd/commit/043696a13171ace7dd4c2b32d34ce039ab629052 patch
- https://github.com/canonical/lxd/commit/7046979645c2ce1b63b2f9e60ddf6cbc4c4b78f9 patch
- https://github.com/canonical/lxd/commit/b7b411caf5c4971bfe2386c72128f44d7e2aaf4f patch
- https://discourse.ubuntu.com/t/lxd-authenticated-remote-code-execution-fixes-available/78365 media-coverage