CVE-2026-41684 | Incus: Nil Dereferences on Restore via Malformed YAML

Exp

Incus is a system container and virtual machine manager. Prior to version 7.0.0, backup.GetInfo() trusts the inline backup/index.yaml config when present and only falls back to parsing the legacy backup/container/backup.yaml file if result.Config == nil. As a result, an archive can carry a valid inline config that passes the initial import preflight while also carrying a malformed legacy backup/container/backup.yaml file that is reparsed later from the restored file system. ParseConfigYamlFile() accepts YAML documents with no container section, and multiple downstream consumers then dereference. Container without checking for nil. Confirmed examples in the instance restore and import flow include backup.UpdateInstanceConfig() and internalImportFromBackup(). An authenticated user with permission to import instance backups may be able to crash the Incus daemon with a crafted backup archive whose inline backup/index.yaml is valid but whose extracted legacy backup.yaml omits container. The crash occurs in the restore path after archive extraction has begun. This issue has been patched in version 7.0.0.

Published: 2026-05-07 Last update: 2026-05-07 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-41684 is rated Exploit Available (50/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.02%). Core evidence: 1 public exploit reference(s) are indexed (Exploit-DB). Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2026-41684

EDB-ID Source Kind Published Link
nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2026-41684

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-22 0.06% 0.02% -0.04%
2 2026-05-08 0.06%

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-41684

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.8 3.6 [email protected]

Weakness enumeration for CVE-2026-41684

GitHub Security Advisory for CVE-2026-41684

GHSA-x5r6-jr56-89pv · Severity: medium · Ecosystem: go — Incus has Nil Dereferences on Restore via Malformed YAML

OS Trackers for CVE-2026-41684

vendor priority summary link
debian not yet assigned CVE-2026-41684 not yet assigned priority: Debian including 2 source packages (incus, lxd), 5 status rows across 4 suites (bookworm, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2026-41684
ubuntu medium CVE-2026-41684 medium priority: Ubuntu including 2 source packages (incus, lxd), 13 status rows across 8 suites (bionic, focal, jammy, noble, questing, resolute, upstream, xenial): needs-triage 8, DNE 5. https://ubuntu.com/security/CVE-2026-41684

Affected software / configurations for CVE-2026-41684

Vendor Product Version Raw CPE
linuxcontainers incus < 7.0.0 cpe:2.3:a:linuxcontainers:incus:*:*:*:*:*:*:*:*

References for CVE-2026-41684

cvelogic Threat Intelligence