CVE-2026-9639
Authenticated Denial of Service via Malicious Backup Tarball in LXD
Description
Nil-pointer dereference in CreateCustomVolumeFromBackup in LXD up to version 6.8 and 5.21 on Linux allows an authenticated user with can_create_storage_volumes permissions to cause a denial of service via a specially crafted custom-volume backup tarball that omits the expires_at snapshot field.
INFO
Published Date :
June 26, 2026, 4:16 p.m.
Last Modified :
July 2, 2026, 1:47 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | cc1ad9ee-3454-478d-9317-d3e869d708bc | ||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update LXD to a version later than 6.8 or 5.21.
- Validate backup tarball integrity before creating volumes.
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-2026-9639.
| URL | Resource |
|---|---|
| https://github.com/canonical/lxd/pull/18320 | Issue Tracking Patch |
| https://github.com/canonical/lxd/pull/18390 | Issue Tracking Patch |
| https://github.com/canonical/lxd/security/advisories/GHSA-j93m-3j9p-m5m8 | Exploit Patch Vendor Advisory |
| https://github.com/canonical/lxd/security/advisories/GHSA-j93m-3j9p-m5m8 | Exploit Patch Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-9639 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-2026-9639
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-2026-9639 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-9639 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.
-
Initial Analysis by [email protected]
Jul. 02, 2026
Action Type Old Value New Value Added CPE Configuration AND OR *cpe:2.3:a:canonical:lxd:*:*:*:*:*:*:*:* versions from (including) 6.0 up to (excluding) 6.9 *cpe:2.3:a:canonical:lxd:*:*:*:*:*:*:*:* versions from (including) 5.0.0 up to (excluding) 5.21.5 OR cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:* Added Reference Type Canonical Ltd.: https://github.com/canonical/lxd/pull/18320 Types: Issue Tracking, Patch Added Reference Type Canonical Ltd.: https://github.com/canonical/lxd/pull/18390 Types: Issue Tracking, Patch Added Reference Type Canonical Ltd.: https://github.com/canonical/lxd/security/advisories/GHSA-j93m-3j9p-m5m8 Types: Exploit, Patch, Vendor Advisory Added Reference Type CISA-ADP: https://github.com/canonical/lxd/security/advisories/GHSA-j93m-3j9p-m5m8 Types: Exploit, Patch, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 26, 2026
Action Type Old Value New Value Added Reference https://github.com/canonical/lxd/security/advisories/GHSA-j93m-3j9p-m5m8 Added SSVC {'id': 'CVE-2026-9639', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-06-26T16:01:50.334142Z'} -
New CVE Received by [email protected]
Jun. 26, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://github.com/canonical/lxd', 'vendor': 'Canonical', 'product': 'LXD', 'versions': [{'status': 'affected', 'version': '5.21.0', 'lessThan': '5.21.5', 'versionType': 'semver'}, {'status': 'affected', 'version': '6.0', 'lessThan': '6.9', 'versionType': 'semver'}], 'platforms': ['Linux'], 'packageName': 'LXD', 'defaultStatus': 'unaffected'}] Added Description Nil-pointer dereference in CreateCustomVolumeFromBackup in LXD up to version 6.8 and 5.21 on Linux allows an authenticated user with can_create_storage_volumes permissions to cause a denial of service via a specially crafted custom-volume backup tarball that omits the expires_at snapshot field. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-476 Added Reference https://github.com/canonical/lxd/pull/18320 Added Reference https://github.com/canonical/lxd/pull/18390 Added Reference https://github.com/canonical/lxd/security/advisories/GHSA-j93m-3j9p-m5m8