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.
Incus is a system container and virtual machine manager. Prior to version 7.0.0, user provided image and backup tarballs would be unpacked and YAML files parsed without any size restrictions. This was making it easy for an authenticated user to provide a crafted image or backup tarball that when parsed by Incus would lead to a very large YAML document being loaded into memory, potentially causing the entire server to run out of memory. This issue has been patched in version 7.0.0.
Incus is a system container and virtual machine manager. Prior to version 7.0.0, a missing error handling could lead an authenticated Incus user to cause a daemon crash through the import of a truncated storage bucket backup file. This issue has been patched in version 7.0.0.
Incus is a system container and virtual machine manager. In versions before 7.0.0, missing validation logic in the storage volume import logic allows an authenticated user with access to the storage volume feature to cause the Incus daemon to crash. The backup restore subsystem contains an out-of-bounds panic vulnerability caused by an invalid bounds check when indexing snapshot metadata arrays, and the same flawed pattern also appears in the migration path. When iterating through physical snapshots provided in a backup archive, the loop uses the index to look up corresponding metadata in the parsed `Config.Snapshots` and `Config.VolumeSnapshots` slices. The guard condition `len(slice) >= i-1` is incorrect because it can still evaluate to true when the subsequent slice[i] access is out of bounds.
An attacker can submit a backup archive that contains physical snapshot directories while supplying a tampered `index.yaml` with an empty or truncated snapshot metadata array, causing the daemon to index beyond the end of the metadata slice and crash. 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.
Incus is a system container and virtual machine manager. In versions before 7.0.0, broken TLS validation logic in the OVN database connection logic can allow connections to an attacker's OVN database. The OVN client implementations disable Go standard TLS server verification and replace it with custom peer-certificate verification logic. That replacement verifier does not anchor trust in the configured CA certificate. Instead, it constructs the verification root set from certificates supplied by the peer during the handshake, so the configured CA is parsed but not used as the trust anchor for the final verification decision.
In OVN-enabled deployments that use these SSL database connection paths, an attacker able to impersonate or intercept the OVN endpoint on the management network can present a rogue self-signed certificate chain, and Incus will accept this certificate as valid. This issue defeats the intended CA-based trust model for OVN database connections and permits endpoint impersonation by an active attacker in a suitable network position. This issue is fixed in version 7.0.0.
Incus is a system container and virtual machine manager. In versions before 7.0.0, missing validation logic in the storage volume import logic allows an authenticated user with access to the storage volume feature to cause the Incus daemon to crash. The custom volume backup import subsystem contains a nil-pointer dereference vulnerability during import operations. In the snapshot import loop, the daemon iterates over entries from `srcBackup.Config.VolumeSnapshots` and assumes that each slice element is initialized, then dereferences fields such as `Name`, `Config`, `Description`, `CreatedAt`, and `ExpiresAt` without first validating the element itself. Because the yaml unmarshaler accepts explicit null array elements from an attacker-controlled index.yaml and converts them into nil pointers inside the slice, an attacker can supply a backup archive containing a null entry in the volume_snapshots array. This causes a nil-pointer dereference during custom volume import and terminates the daemon, resulting in denial of service on the affected node. 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.
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.
CVE-2026-35527 is a Server-Side Request Forgery (SSRF) vulnerability in the Incus container and virtual machine manager versions prior to 7.0.0. The issue arises because the image import flow issues an outbound HEAD request to a user-supplied URL before validating project restrictions. This allows an authenticated user to cause the daemon to send blind HEAD requests to arbitrary destinations, potentially probing internal services or cloud metadata endpoints. Additionally, these requests include server metadata in custom headers, disclosing host environment information. The vulnerability has been fixed in version 7.0.0.
CVE-2026-33945 is a critical path traversal vulnerability in the Incus container and virtual machine manager prior to version 6.23.0. It allows an attacker with limited privileges to write arbitrary files as root outside the intended credentials directory by exploiting the way Incus parses systemd credential configuration keys. This can lead to privilege escalation and denial of service. The vulnerability is fixed in version 6.23.0.
Incus is a system container and virtual machine manager. Prior to version 6.23.0, the web server spawned by `incus webui` incorrectly validates the authentication token such that an invalid value will be accepted. `incus webui` runs a local web server on a random localhost port. For authentication, it provides the user with a URL containing an authentication token. When accessed with that token, Incus creates a cookie persisting that token without needing to include it in subsequent HTTP requests. While the Incus client correctly validates the value of the cookie, it does not correctly validate the token when passed int the URL.
This allows for an attacker able to locate and talk to the temporary web server on localhost to have as much access to Incus as the user who ran `incus webui`. This can lead to privilege escalation by another local user or an access to the user's Incus instances and possibly system resources by a remote attack able to trick the local user into interacting with the Incus UI web server. Version 6.23.0 patches the issue.
CVE-2026-33897 is a critical vulnerability in the lxc incus container and virtual machine manager prior to version 6.23.0. It involves improper neutralization of special elements in the pongo2 template engine used within instances, allowing arbitrary read and write operations on the host filesystem with root privileges. The vulnerability arises because the pongo2 chroot isolation mechanism is bypassed, enabling templates to access and modify the entire system filesystem. This flaw has a CVSS score of 10, indicating a critical severity. Version 6.23.0 of incus includes a patch that addresses this issue.
CVE-2026-33743 is a medium severity vulnerability in the Incus system container and virtual machine manager prior to version 6.23.0. It involves allocation of resources without limits or throttling when processing specially crafted storage bucket backups. An attacker with access to the storage bucket feature can exploit this to crash the Incus daemon, causing a denial of service of the control plane API. This does not affect running workloads or existing containers and virtual machines, which continue operating normally. The issue is fixed in version 6.23.0.
CVE-2026-33711 is a medium severity vulnerability in Incus, a system container and VM manager, affecting versions prior to 6.23.0. The vulnerability arises from the use of predictable temporary file paths under /tmp for VM screenshots, allowing a local attacker to create symlinks that can be abused. On most Linux systems, a kernel security feature called protected_symlinks prevents exploitation, resulting in a permission denied error. However, on systems where this feature is disabled, an attacker can cause Incus to truncate and modify arbitrary files, potentially leading to denial of service or local privilege escalation. The issue is fixed in version 6.23.0.
Incus is a system container and virtual machine manager. Prior to version 6.23.0, a lack of validation of the image fingerprint when downloading from simplestreams image servers opens the door to image cache poisoning and under very narrow circumstances exposes other tenants to running attacker controlled images rather than the expected one. Version 6.23.0 patches the issue.
IncusOS is an immutable OS image dedicated to running Incus. Prior to 202603142010, the default configuration of systemd-cryptenroll as used by IncusOS through mkosi allows for an attacker with physical access to the machine to access the encrypted data without requiring any interaction by the system's owner or any tampering of Secure Boot state or kernel (UKI) boot image. That's because in this configuration, the LUKS key is made available by the TPM so long as the system has the expected PCR7 value and the PCR11 policy matches. That default PCR11 policy importantly allows for the TPM to release the key to the booted system rather than just from the initrd part of the signed kernel image (UKI). The attack relies on the attacker being able to substitute the original encrypted root partition for one that they control. By doing so, the system will prompt for a recovery key on boot, which the attacker has defined and can provide, before booting the system using the attacker's root partition rather than the system's original one. The attacker only needs to put a systemd unit starting on system boot within their root partition to have the system run that logic on boot. That unit will then run in an environment where the TPM will allow for the retrieval of the encryption key of the real root disk, allowing the attacker to steal the LUKS volume key (immutable master key) and then use it against the real root disk, altering it or getting data out before putting the disk back the way it was and returning the system without a trace of this attack having happened. This is all possible because the system will have still booted with Secure Boot enabled, will have measured and ran the expected bootloader and kernel image (UKI). The initrd selects the root disk based on GPT partition identifiers making it possible to easily substitute the real root disk for an attacker controlled one. This doesn't lead to any change in the TPM state and therefore allows for retrieval of the LUKS key by the attacker through a boot time systemd unit on their alternative root partition. IncusOS version 202603142010 (2026/03/14 20:10 UTC) includes the new PCR15 logic and will automatically update the TPM policy on boot. Anyone suspecting that their system may have been physically accessed while shut down should perform a full system wipe and reinstallation as only that will rotate the LUKS volume key and prevent subsequent access to the encrypted data should the system have been previously compromised. There are no known workarounds other than updating to a version with corrected logic which will automatically rebind the LUKS keys to the new set of TPM registers and prevent this from being exploited.
Incus is a system container and virtual machine manager. Versions 6.21.0 and below allow a user with the ability to launch a container with a custom image (e.g a member of the ‘incus’ group) to use directory traversal or symbolic links in the templating functionality to achieve host arbitrary file read, and host arbitrary file write. This ultimately results in arbitrary command execution on the host. When using an image with a metadata.yaml containing templates, both the source and target paths are not checked for symbolic links or directory traversal. This can also be exploited in IncusOS. A fix is planned for versions 6.0.6 and 6.21.0, but they have not been released at the time of publication.
Incus is a system container and virtual machine manager. In versions 6.20.0 and below, a user with the ability to launch a container with a custom YAML configuration (e.g a member of the ‘incus’ group) can create an environment variable containing newlines, which can be used to add additional configuration items in the container’s lxc.conf due to newline injection. This can allow adding arbitrary lifecycle hooks, ultimately resulting in arbitrary command execution on the host. Exploiting this issue on IncusOS requires a slight modification of the payload to change to a different writable directory for the validation step (e.g /tmp). This can be confirmed with a second container with /tmp mounted from the host (A privileged action for validation only). A fix is planned for versions 6.0.6
and 6.21.0, but they have not been released at the time of publication.
Incus is a system container and virtual machine manager. An issue in versions prior to 6.0.6 and 6.19.0 affects any Incus user in an environment where an unprivileged user may have root access to a container with an attached custom storage volume that has the `security.shifted` property set to `true` as well as access to the host as an unprivileged user. The most common case for this would be systems using `incus-user` with the less privileged `incus` group to provide unprivileged users with an isolated restricted access to Incus. Such users may be able to create a custom storage volume with the necessary property (depending on kernel and filesystem support) and can then write a setuid binary from within the container which can be executed as an unprivileged user on the host to gain root privileges. A patch for this issue is expected in versions 6.0.6 and 6.19.0. As a workaround, permissions can be manually restricted until a patched version of Incus is deployed.
Incus is a system container and virtual machine manager. When using an ACL on a device connected to a bridge, Incus versions 6.12 and 6.13generates nftables rules that partially bypass security options `security.mac_filtering`, `security.ipv4_filtering` and `security.ipv6_filtering`. This can lead to ARP spoofing on the bridge and to fully spoof another VM/container on the same bridge. Commit 254dfd2483ab8de39b47c2258b7f1cf0759231c8 contains a patch for the issue.
Incus is a system container and virtual machine manager. When using an ACL on a device connected to a bridge, Incus version 6.12 and 6.13 generates nftables rules for local services (DHCP, DNS...) that partially bypass security options `security.mac_filtering`, `security.ipv4_filtering` and `security.ipv6_filtering`. This can lead to DHCP pool exhaustion and opens the door for other attacks. A patch is available at commit 2516fb19ad8428454cb4edfe70c0a5f0dc1da214.
