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RUSTSEC-2026-0147

CriticalCVSS 10 / 10
Published May 16, 2026·Last modified May 20, 2026
Affected Components(0)

No affected components available

Description

Affected versions of boxlite mount host directories shared via virtiofs as guest-side read-only by setting MS_RDONLY from the guest. Because the default guest capability set included CAP_SYS_ADMIN, untrusted code running inside a sandbox could execute mount -o remount,rw <path> to re-flag the share as read-write and then write through to the host filesystem — fully escaping the read-only contract boxlite advertised to callers.

The fix in v0.9.0 enforces read-only at the hypervisor level via krun_add_virtiofs3 (so the guest's MS_RDONLY is no longer the authoritative gate) and drops CAP_SYS_ADMIN from the default guest capability set (matching Docker's defaults).

This is a sandbox-escape bug: boxlite is a sandboxing runtime, so the read-only invariant is part of its security contract. CVSS rated 10.0 by the upstream advisory.

Risk Scores
Base Score
10.0

The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker does not need any special privileges or access rights. No user interaction is needed for the attacker to exploit this vulnerability. The vulnerability can affect other systems as well, not just the initial system. There is a high impact on the confidentiality of the information. There is a high impact on the integrity of the data. There is a high impact on the availability of the system.

Threat Intelligence
9.1

Active exploitation in the wild has been confirmed. Immediate patching or mitigation is required.

EPSS
0.29%

The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

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