Description
Confidential Containers Guest Components provides guest tools and components for confidential container workloads. From 0.16.0 until 0.20.0, a crafted OCI image layer can make image_rs::stream::unpack::unpack() create a hardlink outside its destination directory. In image-rs/src/stream/unpack.rs, try_hardlink_fallback() validates the hardlink source but computes the destination with destination.join(&entry_rel). Rust Path::join replaces the base when entry_rel is an absolute tar entry path, so fs::hard_link(&src_canon, &dst_entry_abs) can write attacker-controlled content to an arbitrary absolute path. In Confidential Containers the workload owner already controls trusted image content, so the issue is a workload-owner escape into the pod virtual machine rather than a crossing of the image trust boundary, but it may enable access to pod virtual machine capabilities and attestation abuse. This issue is fixed in version 0.20.0.
References6
- github.com/confidential-containers/guest-components/commit/14fb…
- github.com/confidential-containers/guest-components/commit/7cc1…
- github.com/confidential-containers/guest-components/pull/1440
- github.com/confidential-containers/guest-components/pull/1457
- github.com/confidential-containers/guest-components/releases/ta…
- github.com/confidential-containers/guest-components/security/ad…
Metrics
- CVSS 3.1
-
6.4
MEDIUM
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N - EPSS — exploit probability
- 0% percentile: 22 · as of 10 November 2026
- CWE
- CWE-22CWE-59
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.