CVE-2026-66898
Path traversal via unvalidated instance name in backup tarball restore enables root file write / RCE
Description
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.
INFO
Published Date :
Aug. 12, 2026, 9:17 p.m.
Last Modified :
Aug. 12, 2026, 9:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | CRITICAL | cc1ad9ee-3454-478d-9317-d3e869d708bc | ||||
| CVSS 3.1 | CRITICAL | [email protected] |
Solution
- Ensure LXD properly validates instance and storage volume names.
- Sanitize all path components within backup archives.
- Apply input validation to prevent path traversal.
- Update LXD to the latest secure version.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-66898.
| URL | Resource |
|---|---|
| https://github.com/canonical/lxd/security/advisories/GHSA-m857-c7gc-c984 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-66898 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-66898
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-66898 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-66898 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
Aug. 12, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://github.com/canonical/lxd', 'vendor': 'Canonical', 'product': 'LXD', 'versions': [{'status': 'affected', 'version': '4.0.0', 'lessThan': '4.0.12', 'versionType': 'semver'}, {'status': 'affected', 'version': '5.0.0', 'lessThan': '5.0.4', 'versionType': 'semver'}, {'status': 'affected', 'version': '5.21.0', 'lessThan': '5.21.2', 'versionType': 'semver'}, {'status': 'affected', 'version': '6.0', 'lessThan': '6.1', 'versionType': 'semver'}], 'platforms': ['Linux'], 'packageName': 'LXD', 'defaultStatus': 'unaffected'}] Added Description 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. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H Added CWE CWE-22 Added Reference https://github.com/canonical/lxd/security/advisories/GHSA-m857-c7gc-c984