What is CVE-2026-9639?

CVE-2026-9639 is a medium-severity vulnerability in Linux Kernel, classified under NULL Pointer Dereference. CVSS score: 6.5/10. Published 2026-06-26.

How severe is CVE-2026-9639?

Medium severity. CVSS v3 base score is 6.5 out of 10.

NULL pointer dereference in Linux Kernel

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.

Published 2026-06-26 · last modified 2026-07-02.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.005 (43.7th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 44th percentile — 43.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000

Affected products

Linux Kernel
Canonical Lxd — versions 5.21.0, 6.0

Weakness classification (CWE)

CWE-476 — NULL Pointer Dereference

References

github.com/canonical/lxd/security/advisories/GHSA-j93m-3j9p-m5m8 (Exploit, vendor-advisory, Patch, vdb-entry, Vendor Advisory)
github.com/canonical/lxd/pull/18320 (Patch, patch, Issue Tracking)
github.com/canonical/lxd/pull/18390 (Patch, patch, Issue Tracking)

Frequently asked questions

What is CVE-2026-9639?: CVE-2026-9639 is a medium-severity vulnerability in Linux Kernel, classified under NULL Pointer Dereference. CVSS score: 6.5/10. Published 2026-06-26.
How severe is CVE-2026-9639?: Medium severity. CVSS v3 base score is 6.5 out of 10.