Boxlite, a sandbox service, fails to restrict kernel capabilities in containers before version 0.9.0. Malicious code running inside a container can remount a read‑only directory with read‑write permissions, allowing arbitrary writes to files that should be immutable. This privilege‑bypass flaw, categorized as CWE‑284, enables an attacker to tamper with critical configuration or data files, potentially compromising the integrity and confidentiality of the sandboxed environment.

The vulnerability affects all Boxlite versions prior to 0.9.0 released by the vendor boxlite‑ai. The patch that resolves the issue is included in release v0.9.0.

With a CVSS score of 10, the flaw is considered critical. The EPSS metric is not available, and the vulnerability is not listed in the CISA KEV catalog. Exploitation requires code execution within the Boxlite container; a user or attacker who can run arbitrary code inside the sandbox can remount a directory and modify its contents. The high severity rating reflects the potential for widespread data tampering once the vulnerability is abused.