CVE-2026-66898
Path traversal via unvalidated instance name in backup tarball restore enables root file write / RCE
A path traversal vulnerability in LXD allows an attacker to manipulate file system paths during backup import and restore operations. When importing or restoring a backup archive, LXD fails to validate instance and storage volume names contained within the archive metadata. An attacker can exploit this flaw by supplying a crafted backup archive with malicious instance or volume names containing path traversal sequences, potentially allowing file access or overwriting outside the designated restore directory.
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
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Path traversal via unvalidated instance name in backup tarball restore enables root file write / RCE
A path traversal vulnerability in LXD allows an attacker to manipulate file system paths during backup import and restore operations. When importing or restoring a backup archive, LXD fails to validate instance and storage volume names contained within the archive metadata. An attacker can exploit this flaw by supplying a crafted backup archive with malicious instance or volume names containing path traversal sequences, potentially allowing file access or overwriting outside the designated restore directory.
- Record
CVE-2026-66898- CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-22
- Updated
- 2026-11-02
EUVDEUVD-2026-57545
A path traversal vulnerability in LXD allows an attacker to manipulate file system paths during backup import and restore operations. When importing or restoring a backup archive, LXD fails to validate instance and storage volume names contained within the archive metadata. An attacker can exploit this flaw by supplying a crafted backup archive with malicious instance or volume names containing path traversal sequences, potentially allowing file access or overwriting outside the designated restore directory.
- Record
EUVD-2026-57545- CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Updated
- 2026-11-02
NVD
A path traversal vulnerability in LXD allows an attacker to manipulate file system paths during backup import and restore operations. When importing or restoring a backup archive, LXD fails to validate instance and storage volume names contained within the archive metadata. An attacker can exploit this flaw by supplying a crafted backup archive with malicious instance or volume names containing path traversal sequences, potentially allowing file access or overwriting outside the designated restore directory.
- Record
CVE-2026-66898- CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-22
- Updated
- 2026-11-02
OSV
Path traversal via unvalidated instance name in backup tarball restore enables root file write / RCE
A path traversal vulnerability in LXD allows an attacker to manipulate file system paths during backup import and restore operations. When importing or restoring a backup archive, LXD fails to validate instance and storage volume names contained within the archive metadata. An attacker can exploit this flaw by supplying a crafted backup archive with malicious instance or volume names containing path traversal sequences, potentially allowing file access or overwriting outside the designated restore directory.
- Record
CVE-2026-66898- CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-22
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-66898
A path traversal vulnerability in LXD allows an attacker to manipulate file system paths during backup import and restore operations. When importing or restoring a backup archive, LXD fails to validate instance and storage volume names contained within the archive metadata. An attacker can exploit this flaw by supplying a crafted backup archive with malicious instance or volume names containing path traversal sequences, potentially allowing file access or overwriting outside the designated restore directory.
- Record
DEBIAN-CVE-2026-66898- CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-66898
A path traversal vulnerability in LXD allows an attacker to manipulate file system paths during backup import and restore operations. When importing or restoring a backup archive, LXD fails to validate instance and storage volume names contained within the archive metadata. An attacker can exploit this flaw by supplying a crafted backup archive with malicious instance or volume names containing path traversal sequences, potentially allowing file access or overwriting outside the designated restore directory.
- Record
UBUNTU-CVE-2026-66898- CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Updated
- 2026-11-02
OSVopenSUSE-SU-2026:21788-1 No score
Security update for lxd
This update for lxd fixes the following issues:
Changes in lxd:
-
update to 5.21.6:
- bsc#1274937, CVE-2026-63293, bsc#1274936, CVE-2026-62420, bsc#1274954, CVE-2026-63295, bsc#1274963, CVE-2026-63297, bsc#1274961, CVE-2026-63296, bsc#1275085, CVE-2026-63299, bsc#1275084, CVE-2026-63298, bsc#1275090, CVE-2026-66898
- https://canonical.com/lxd/docs/latest/reference/release- notes/5.21/release-notes-5.21.6/
- https://canonical.com/lxd/docs/latest/reference/release- notes/5.21/release-notes-5.21.5/
- https://discourse.ubuntu.com/t/lxd-5-21-4-lts-has-been- released/66602
- https://discourse.ubuntu.com/t/lxd-5-21-3-lts-has-been- released/53768
- https://discourse.ubuntu.com/t/lxd-5-21-2-has-been- released/46443
-
Migrate to single LXD/Incus OVMF handling (lxd-ovmf-setup):
- Allow aarch64 arch_vm_support
- Remove OVMF symlinks
- Require the new lxd-ovmf-setup packages
- Record
openSUSE-SU-2026:21788-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
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 |
lxdopenSUSE:Leap 16.0 |
before 5.21.6-bp160.1.1 | 5.21.6-bp160.1.1 |
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-2026-66898 is a critical vulnerability (CVSS 9.9) in Canonical Lxd, published August 12, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.59%, the 48th percentile. Fixed in lxd 5.21.6-bp160.1.1.
References
github.com/canonical/lxd/security/advisories/GHSA-m857-c7gc-c984
nvd.nist.gov/vuln/detail/CVE-2026-66898
security-tracker.debian.org/tracker/CVE-2026-66898
ubuntu.com/security/CVE-2026-66898
Show 19 moreShow less
cve.org/CVERecord?id=CVE-2026-66898
bugzilla.suse.com/1223794
suse.com/security/cve/CVE-2023-46565
Left out here: 26 versions. The JSON record has them.