{"schema_version":"1.9.0","id":"RUSTSEC-2026-0147","published":"2026-05-16T12:00:00Z","modified":"2026-10-12T18:00:13.061473890Z","aliases":["CVE-2026-46695","GHSA-g6ww-w5j2-r7x3","GO-2026-5392","PYSEC-2026-299"],"summary":"Read-only volume remount bypass via guest CAP_SYS_ADMIN","details":"Affected versions of `boxlite` mount host directories shared via virtiofs\nas guest-side read-only by setting `MS_RDONLY` from the guest. Because the\ndefault guest capability set included `CAP_SYS_ADMIN`, untrusted code\nrunning inside a sandbox could execute `mount -o remount,rw <path>` to\nre-flag the share as read-write and then write through to the host\nfilesystem — fully escaping the read-only contract `boxlite` advertised\nto callers.\n\nThe fix in v0.9.0 enforces read-only at the hypervisor level via\n`krun_add_virtiofs3` (so the guest's `MS_RDONLY` is no longer the\nauthoritative gate) and drops `CAP_SYS_ADMIN` from the default guest\ncapability set (matching Docker's defaults).\n\nThis is a sandbox-escape bug: `boxlite` is a sandboxing runtime, so the\nread-only invariant is part of its security contract. CVSS rated 10.0 by\nthe upstream advisory.","affected":[{"package":{"name":"boxlite","ecosystem":"crates.io","purl":"pkg:cargo/boxlite"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0.0.0-0"},{"fixed":"0.9.0"}]}],"ecosystem_specific":{"affected_functions":null,"affects":{"arch":[],"functions":[],"os":[]}},"database_specific":{"categories":["privilege-escalation"],"cvss":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","informational":null,"source":"https://github.com/rustsec/advisory-db/blob/osv/crates/RUSTSEC-2026-0147.json"}}],"references":[{"type":"PACKAGE","url":"https://crates.io/crates/boxlite"},{"type":"ADVISORY","url":"https://rustsec.org/advisories/RUSTSEC-2026-0147.html"},{"type":"WEB","url":"https://github.com/boxlite-ai/boxlite/pull/454"},{"type":"WEB","url":"https://github.com/boxlite-ai/boxlite/pull/454"}],"database_specific":{"license":"CC0-1.0"},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H"}]}