CVE-2026-9639 json
Authenticated Denial of Service via Malicious Backup Tarball in LXD
published 2026-06-26 4 mo ago modified 2026-11-06 2 d ago also GHSA-j93m-3j9p-m5m8 , EUVD-2026-39789
- cvss
- 6.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.5%
- EPSS 0.5% chance of exploitation in 30 days, percentile 46%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- go github.com/canonical/lxd 0.0.0-20260622081844-85f897013ccd
- Canonical LXD 5.21.5, 6.9
- lxd Debian 13 5.0.2+git20231211.1364ae4-9+deb13u7
debian advisories DEBIAN-CVE-2026-9639
- github.com/canonical/lxd@05bc272 commit
- github.com/canonical/lxd@c7cdfad commit
- github.com/canonical/lxd@d155208 commit
- github.com/canonical/lxd#18320 pull request
- github.com/canonical/lxd#18390 pull request
- github.com/canonical/lxd/releases/tag/lxd-5.21.5 release
- github.com/canonical/lxd/releases/tag/lxd-6.9 release
- github.com/canonical/lxd/security/advisories/GHSA-j93m-3j9p-m5m8 advisory
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- partial
- Assessed
- 4 mo ago
Exploit prediction
0.55% chance of exploitation in the next 30 days, higher than 46% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/canonical/lxd/security/advisories/GHSA-j93m-3j9p-m5m8 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| GitHub | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| go | github.com/canonical/lxd | <0.0.0-20260622081844-85f897013ccd |
0.0.0-20260622081844-85f897013ccd |
Affected products
- Canonical LXD
Classification
- Weakness
-
- CWE-476 NULL Pointer Dereference
References
-
github.com
/canonical/lxd/pull/18320
patch, web, issue-tracking
-
github.com
/canonical/lxd/pull/18390
patch, web, issue-tracking
-
github.com
/canonical/lxd/security/advisories/GHSA-j93m-3j9p-m5m8
vdb-entry, vendor-advisory, exploit, web, patch
-
github.com
/canonical/lxd/commit/05bc2729e99707a766d5c4705167a3322c9ef424
web
-
github.com
/canonical/lxd/commit/c7cdfadb6044dfeaac592dc225978b4125ee23fe
web
-
github.com
/canonical/lxd/commit/d15520809e6e2ac2af0c6354dfb7be5854b0e859
web
-
nvd.nist.gov
/vuln/detail/CVE-2026-9639
advisory
-
github.com
/CVEProject/cvelistV5/blob/main/cves/2026/9xxx/CVE-2026-9639.json
web
-
github.com
/canonical/lxd
package
-
github.com
/canonical/lxd/blob/lxd-5.0.7/lxd/storage/backend_lxd.go
web
-
github.com
/canonical/lxd/releases/tag/lxd-5.21.5
web
-
github.com
/canonical/lxd/releases/tag/lxd-6.9
web
Sources
- CVE List CVE-2026-9639
- GitHub Advisory GHSA-j93m-3j9p-m5m8
- NVD CVE-2026-9639
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