How severe is CVE-2026-63299?

CVE-2026-63299 has a CVSS 3.x base score of 9.9, rated critical severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-63299 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-63299?

CVE-2026-63299 affects Canonical Lxd. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-63299?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2026-63299 published?

CVE-2026-63299 was published on 2026-08-12 and last updated on 2026-09-11.

CVE-2026-63299

CVE-2026-63299 is a critical-severity vulnerability in Canonical Lxd with a CVSS 3.x base score of 9.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-770.

Key facts

Severity: Critical (CVSS 3.x base score 9.9)
EPSS exploit prediction: 1% (46th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-770
Affected product: Canonical Lxd
Published: 2026-08-12
Last modified: 2026-09-11

Description

An authorization bypass vulnerability in LXD allows an authenticated user to bypass project-level disk and volume limits. Two related code paths fail to verify resource limits during volume operations: the storagePoolVolumeTypePostMove function omits the limits.AllowVolumeCreation check before moving a volume across projects, and volume snapshot restore operations skip the AllowVolumeUpdate check when the configuration is nil (Config == nil). An attacker can exploit these flaws to allocate storage resources that exceed the administrative limits configured for a project.

Frequently asked questions

What is CVE-2026-63299?: An authorization bypass vulnerability in LXD allows an authenticated user to bypass project-level disk and volume limits. Two related code paths fail to verify resource limits during volume operations: the storagePoolVolumeTypePostMove function omits the limits.AllowVolumeCreation check before moving a volume across projects, and volume snapshot restore operations skip the AllowVolumeUpdate check when the configuration is nil (Config == nil). An attacker can exploit these flaws to allocate storage resources that exceed the administrative limits configured for a project.
How severe is CVE-2026-63299?: CVE-2026-63299 has a CVSS 3.x base score of 9.9, rated critical severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-63299 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-63299?: CVE-2026-63299 affects Canonical Lxd. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-63299?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2026-63299 published?: CVE-2026-63299 was published on 2026-08-12 and last updated on 2026-09-11.

References

https://github.com/canonical/lxd/security/advisories/GHSA-5h78-p252-989h

Affected products (1)

cpe:2.3:a:canonical:lxd:*:*:*:*:*:*:*:*

More vulnerabilities in Canonical Lxd

CVE-2026-66897 — Critical (CVSS 9.9): A path traversal vulnerability in LXD's instance template processing allows an attacker with container edit…
CVE-2026-66898 — Critical (CVSS 9.9): A path traversal vulnerability in LXD allows an attacker to manipulate file system paths during backup import and…
CVE-2026-63300 — Critical (CVSS 9.9): An improper validation vulnerability in the instancePostMigration function in lxd/instance_post.go of LXD allows an…
CVE-2026-63298 — Critical (CVSS 9.9): An improper neutralization of special elements vulnerability in LXD's NVIDIA instance configuration handling allows an…
CVE-2026-63297 — Critical (CVSS 9.9): An authorization bypass vulnerability in LXD due to a timing flaw during configuration merging allows an authenticated…
CVE-2026-63296 — Critical (CVSS 9.9): An authorization bypass vulnerability in LXD allows an authenticated attacker to bypass target project restrictions…

All CVEs affecting Canonical Lxd →

Other CWE-770 (Allocation of Resources Without Limits or Throttling) vulnerabilities

CVE-2026-82439 — Critical (CVSS 9.8): Description The DRPC server kept a map from function name to request queue and created an entry the first time…
CVE-2026-47891 — Critical (CVSS 9.8): A Spring WebFlux application that relies on the Aalto XML processor to parse XML input does not correctly enforce the…
CVE-2026-74878 — Critical (CVSS 9.8): openssl_encrypt versions before 1.4.0 use an in-memory rate limiter for TOTP brute-force protection that is not shared…
CVE-2026-31283 — Critical (CVSS 9.8): In Totara LMS v19.1.5 and before, the forgot password API does not implement rate limiting for the target email…
CVE-2020-37067 — Critical (CVSS 9.8): Filetto 1.0 FTP server contains a denial of service vulnerability in the FEAT command processing that allows attackers…
CVE-2021-47875 — Critical (CVSS 9.8): GeoGebra CAS Calculator 6.0.631.0 contains a denial of service vulnerability that allows attackers to crash the…

Browse all CWE-770 (Allocation of Resources Without Limits or Throttling) vulnerabilities →