CVE-2026-46695: BoxLite: Permission Bypass in boxlite Allows Modification of Read-Only Files

Synopsis

A permission bypass in BoxLite, the sandbox service for running untrusted code inside lightweight virtual machines and OCI containers, allows malicious container code to remount read-only directories in read-write mode. The vulnerability is reachable over the network with no authentication required and no user interaction needed, as derived from the CVSS vector. Successful exploitation gives an attacker arbitrary write access to directories that should be read-only, enabling tampering with persisted files across the sandbox boundary. HarborGuard tracks the advisory for patch availability, as no fix version has been published upstream at this time.

HarborGuard Coverage

Exploit Conditions

• Network reachabilityRequired

  The vulnerable service is exposed over the network, meaning an attacker can reach it without requiring local or physical access.

• AuthenticationNot required

  No credentials or account of any kind are needed to trigger the vulnerability.

• Victim interactionNot required

  Exploitation is fully attacker-driven and requires no action from any user or operator.

• Attack complexityDetail

  The exploit is reliable and condition-free, with no race conditions or special environmental factors required to succeed.

Blast Radius

• An attacker can write arbitrary data to directories mounted as read-only inside the BoxLite sandbox, bypassing the intended isolation boundary.
• Malicious container code can tamper with configuration files, binaries, or other persisted content that the sandbox was designed to protect from modification.
• Because the scope is changed (S:C in the CVSS vector), the impact extends beyond the container itself and can affect the underlying host or adjacent resources sharing the same volume mounts.
• Confidentiality of stored data is also compromised, as the same remount capability that enables writes also grants read access to previously restricted directory contents.