CVE-2026-85185
Path traversal in LXD btrfs storage driver allows arbitrary file deletion and write on host as root
Path traversal in the btrfs storage driver in Canonical LXD versions 4.0.2 and later (fixed in 4.0.14, 5.0.10, 5.21.8 and 6.10) on Linux allows an authenticated client with permission to create instances in a project to delete arbitrary files on the host as root. On hosts whose root filesystem is btrfs, the client can also place attacker-controlled content at arbitrary host paths, leading to full host compromise. The client does this with a crafted subvolume path containing ../ sequences, sent in either of two ways: in the optimized_header.yaml of an optimized btrfs backup, or in the btrfs migration header sent by a malicious migration source.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
9.6
Path traversal in LXD btrfs storage driver allows arbitrary file deletion and write on host as root
Path traversal in the btrfs storage driver in Canonical LXD versions 4.0.2 and later (fixed in 4.0.14, 5.0.10, 5.21.8 and 6.10) on Linux allows an authenticated client with permission to create instances in a project to delete arbitrary files on the host as root. On hosts whose root filesystem is btrfs, the client can also place attacker-controlled content at arbitrary host paths, leading to full host compromise. The client does this with a crafted subvolume path containing ../ sequences, sent in either of two ways: in the optimized_header.yaml of an optimized btrfs backup, or in the btrfs migration header sent by a malicious migration source.
- Record
CVE-2026-85185- CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H - Weakness
- CWE-22
- Updated
- 2026-11-02
EUVDEUVD-2026-88258
9.6
Path traversal in the btrfs storage driver in Canonical LXD versions 4.0.2 and later (fixed in 4.0.14, 5.0.10, 5.21.8 and 6.10) on Linux allows an authenticated client with permission to create instances in a project to delete arbitrary files on the host as root. On hosts whose root filesystem is btrfs, the client can also place attacker-controlled content at arbitrary host paths, leading to full host compromise. The client does this with a crafted subvolume path containing ../ sequences, sent in either of two ways: in the optimized_header.yaml of an optimized btrfs backup, or in the btrfs migration header sent by a malicious migration source.
- Record
EUVD-2026-88258- CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H - Updated
- 2026-11-02
NVD
9.6
Path traversal in the btrfs storage driver in Canonical LXD versions 4.0.2 and later (fixed in 4.0.14, 5.0.10, 5.21.8 and 6.10) on Linux allows an authenticated client with permission to create instances in a project to delete arbitrary files on the host as root. On hosts whose root filesystem is btrfs, the client can also place attacker-controlled content at arbitrary host paths, leading to full host compromise. The client does this with a crafted subvolume path containing ../ sequences, sent in either of two ways: in the optimized_header.yaml of an optimized btrfs backup, or in the btrfs migration header sent by a malicious migration source.
- Record
CVE-2026-85185- CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H - Weakness
- CWE-22
- Updated
- 2026-11-02
OSV
9.6
Path traversal in LXD btrfs storage driver allows arbitrary file deletion and write on host as root
Path traversal in the btrfs storage driver in Canonical LXD versions 4.0.2 and later (fixed in 4.0.14, 5.0.10, 5.21.8 and 6.10) on Linux allows an authenticated client with permission to create instances in a project to delete arbitrary files on the host as root. On hosts whose root filesystem is btrfs, the client can also place attacker-controlled content at arbitrary host paths, leading to full host compromise. The client does this with a crafted subvolume path containing ../ sequences, sent in either of two ways: in the optimized_header.yaml of an optimized btrfs backup, or in the btrfs migration header sent by a malicious migration source.
- Record
CVE-2026-85185- CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H - Weakness
- CWE-22
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-85185
9.6
Path traversal in the btrfs storage driver in Canonical LXD versions 4.0.2 and later (fixed in 4.0.14, 5.0.10, 5.21.8 and 6.10) on Linux allows an authenticated client with permission to create instances in a project to delete arbitrary files on the host as root. On hosts whose root filesystem is btrfs, the client can also place attacker-controlled content at arbitrary host paths, leading to full host compromise. The client does this with a crafted subvolume path containing ../ sequences, sent in either of two ways: in the optimized_header.yaml of an optimized btrfs backup, or in the btrfs migration header sent by a malicious migration source.
- Record
DEBIAN-CVE-2026-85185- CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-85185
9.6
Path traversal in the btrfs storage driver in Canonical LXD versions 4.0.2 and later (fixed in 4.0.14, 5.0.10, 5.21.8 and 6.10) on Linux allows an authenticated client with permission to create instances in a project to delete arbitrary files on the host as root. On hosts whose root filesystem is btrfs, the client can also place attacker-controlled content at arbitrary host paths, leading to full host compromise. The client does this with a crafted subvolume path containing ../ sequences, sent in either of two ways: in the optimized_header.yaml of an optimized btrfs backup, or in the btrfs migration header sent by a malicious migration source.
- Record
UBUNTU-CVE-2026-85185- CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H - Updated
- 2026-11-02
OSVopenSUSE-SU-2026:11983-1 No score
incus-7.5.1-1.1 on GA media
These are all security issues fixed in the incus-7.5.1-1.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2026:11983-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
incusDebian:13 |
before 6.0.4-2+deb13u1, plus listed versions 6.0.4-26.0.4-2+deb13u1~bpo12+1 |
6.0.4-2+deb13u1 |
incusDebian:14 |
before 7.0.1-5, plus listed versions 6.0.4-26.0.4-36.0.5-16.0.5-26.0.5-3 Show 31 moreShow less6.0.5-46.0.5-56.0.5-66.0.5-76.0.5-86.0.6-16.0.6-26.0.6-36.14.0-1~exp16.15.0-1~exp16.16.0-1~exp16.17.0-1~exp16.20.0-1~exp16.21.0-1~exp16.22.0-1~exp16.23.0-1~exp17.0.0-17.0.0-1~bpo13+17.0.0-27.0.0-2~bpo13+17.0.0-37.0.0-47.0.0-57.0.0-5~bpo13+17.0.1-17.0.1-1~bpo13+17.0.1-27.0.1-2~bpo13+17.0.1-37.0.1-3~bpo13+17.0.1-4 |
7.0.1-5 |
lxdDebian:12 |
All versions, plus listed versions 5.0.2+git20231211.1364ae4-15.0.2+git20231211.1364ae4-25.0.2+git20231211.1364ae4-35.0.2+git20231211.1364ae4-45.0.2+git20231211.1364ae4-5 Show 12 moreShow less5.0.2+git20231211.1364ae4-65.0.2+git20231211.1364ae4-75.0.2+git20231211.1364ae4-85.0.2+git20231211.1364ae4-95.0.2-55.0.2-5+deb12u15.0.2-5+deb12u25.0.2-5+deb12u35.0.2-5+deb12u45.0.2-5+deb12u55.0.2-5+deb12u65.0.2-6 |
None known |
lxdDebian:13 |
All versions, plus listed versions 5.0.2+git20231211.1364ae4-95.0.2+git20231211.1364ae4-9+deb13u15.0.2+git20231211.1364ae4-9+deb13u25.0.2+git20231211.1364ae4-9+deb13u35.0.2+git20231211.1364ae4-9+deb13u45.0.2+git20231211.1364ae4-9+deb13u55.0.2+git20231211.1364ae4-9+deb13u65.0.2+git20231211.1364ae4-9+deb13u7 |
None known |
lxdUbuntu:Pro:16.04:LTS |
All versions, plus listed versions 0.20-0ubuntu40.21-0ubuntu30.21-0ubuntu50.22-0ubuntu10.22-0ubuntu2 Show 45 moreShow less0.23-0ubuntu10.23-0ubuntu20.23-0ubuntu30.24-0ubuntu20.24-0ubuntu30.24-0ubuntu40.25-0ubuntu10.26-0ubuntu20.26-0ubuntu30.27-0ubuntu10.27-0ubuntu22.0.0~beta1-0ubuntu32.0.0~beta1-0ubuntu42.0.0~beta2-0ubuntu12.0.0~beta2-0ubuntu22.0.0~beta3-0ubuntu12.0.0~beta3-0ubuntu22.0.0~beta3-0ubuntu32.0.0~beta3-0ubuntu42.0.0~beta4-0ubuntu12.0.0~beta4-0ubuntu22.0.0~beta4-0ubuntu32.0.0~beta4-0ubuntu42.0.0~beta4-0ubuntu52.0.0~beta4-0ubuntu62.0.0~beta4-0ubuntu72.0.0~rc1-0ubuntu12.0.0~rc1-0ubuntu22.0.0~rc1-0ubuntu32.0.0~rc2-0ubuntu22.0.0~rc2-0ubuntu32.0.0~rc3-0ubuntu12.0.0~rc3-0ubuntu22.0.0~rc3-0ubuntu32.0.0~rc3-0ubuntu42.0.0~rc4-0ubuntu12.0.0~rc5-0ubuntu12.0.0~rc6-0ubuntu12.0.0~rc6-0ubuntu22.0.0~rc7-0ubuntu12.0.0~rc7-0ubuntu22.0.0~rc8-0ubuntu12.0.0~rc8-0ubuntu22.0.0~rc8-0ubuntu32.0.0~rc8-0ubuntu5 |
None known |
lxdUbuntu:Pro:18.04:LTS |
All versions, plus listed versions 2.18-0ubuntu62.19-0ubuntu12.20-0ubuntu32.20-0ubuntu42.21-0ubuntu1 Show 18 moreShow less2.21-0ubuntu22.21-0ubuntu32.21-0ubuntu43.0.0~beta2-0ubuntu33.0.0~beta3-0ubuntu33.0.0~beta5-0ubuntu23.0.0~beta7-0ubuntu13.0.0-0ubuntu13.0.0-0ubuntu23.0.0-0ubuntu33.0.0-0ubuntu43.0.1-0ubuntu1~18.04.13.0.2-0ubuntu1~18.04.13.0.3-0ubuntu1~18.04.13.0.3-0ubuntu1~18.04.23.0.3-0ubuntu1~18.04.2+esm13.0.3-0ubuntu1~18.04.2+esm23.0.3-0ubuntu1~18.04.2+esm3 |
None known |
lxdUbuntu:20.04:LTS |
All versions, plus listed versions 1:0.71:0.81:0.91:0.10 |
None known |
incusUbuntu:Pro:24.04:LTS |
All versions, plus listed versions 0.4-1ubuntu10.5.1-10.5.1-30.6-16.0.0-1 Show 7 moreShow less6.0.0-1ubuntu0.16.0.0-1ubuntu0.26.0.0-1ubuntu0.2+esm16.0.0-1ubuntu0.36.0.0-1ubuntu0.3+esm16.0.0-1ubuntu0.3+esm26.0.0-1ubuntu0.3+esm3 |
None known |
incusUbuntu:26.10 |
All versions, plus listed versions 6.0.5-87.0.1-5 |
None known |
incusUbuntu:Pro:26.04:LTS |
All versions, plus listed versions 6.0.4-26.0.5-86.0.5-8ubuntu0.26.04.1~esm1 |
None known |
incusopenSUSE:Tumbleweed |
before 7.5.1-1.1 | 7.5.1-1.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-85185 is a critical vulnerability (CVSS 9.6) in Canonical Lxd, published September 28, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.37%, the 30th percentile. Fixed in incus 6.0.4-2+deb13u1.
References
github.com/canonical/lxd/security/advisories/GHSA-27q7-qwhm-c34p
github.com/CVEProject/cvelistV5/tree/main/cves/2026/85xxx/CVE-2026-85185.json
nvd.nist.gov/vuln/detail/CVE-2026-85185
github.com/canonical/lxd
security-tracker.debian.org/tracker/CVE-2026-85185
ubuntu.com/security/CVE-2026-85185
cve.org/CVERecord?id=CVE-2026-85185
suse.com/security/cve/CVE-2026-85185
suse.com/security/cve/CVE-2026-85526
Left out here: 26 versions. The JSON record has them.