CVE-2026-9639

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.

CVSS v3.1 Score

6.5

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS — Exploit Prediction

0.0039

Probability of exploitation

0.31%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-476 CWE-476

Affected Products

Vendor	Product	Versions
canonical	lxd	5.0.0 — 5.21.5
canonical	lxd	6.0 — 6.9
linux	linux_kernel	All

References

Advisories & Patches

https://github.com/canonical/lxd/pull/18320 https://github.com/canonical/lxd/pull/18390 https://github.com/canonical/lxd/security/advisories/GHSA-j93m-3j9p-m5m8 https://github.com/canonical/lxd/security/advisories/GHSA-j93m-3j9p-m5m8

Exploits

https://github.com/canonical/lxd/security/advisories/GHSA-j93m-3j9p-m5m8 https://github.com/canonical/lxd/security/advisories/GHSA-j93m-3j9p-m5m8

Frequently Asked Questions

What is CVE-2026-9639? +

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. It has a CVSS v3.1 base score of 6.5 (MEDIUM).

How severe is CVE-2026-9639? +

CVE-2026-9639 has a CVSS v3.1 score of 6.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0039, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-9639? +

CVE-2026-9639 affects products from canonical, linux, specifically: linux_kernel, lxd. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-9639? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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