Youki: If /proc and /sys in the rootfs are symbolic links, they can potentially be exploited to gain access to the host root filesystem.

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.0 · CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS

• CVE-2025-54867: 0.18% estimated exploitation activity in the next 30 days; percentile 7.92 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary If /proc and /sys in the rootfs are symbolic links, they can potentially be exploited to gain access to the host root filesystem. Details For security reasons, container creation should be prohibited if /proc or /sys in the rootfs is a symbolic link. I verified this behavior with youki. When /proc or /sys is a symbolic link, runc fails to create the container, whereas youki successfully creates it. This is the fix related to this issue in runc. https://github.com/opencontainers/runc/pull/3756 https://github.com/opencontainers/runc/pull/3773 https://github.com/opencontainers/runc/blob/main/libcontainer/rootfslinux.go#L590 https://github.com/opencontainers/runc/blob/main/tests/integration/mask.bats#L60 Impact The following advisory appears to be related to this vulnerability: https://github.com/advisories/GHSA-vpvm-3wq2-2wvm https://github.com/advisories/GHSA-fh74-hm69-rqjw

Published by the source

14 Aug 2025, 16:39 UTC

Last modified by the source

14 Aug 2025, 19:37 UTC

Source last checked

26 Oct 2026, 15:39 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-j26p-6wx7-f3pw

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# Patch Next advisory brief: CVE-2025-54867

Advisory: Youki: If /proc and /sys in the rootfs are symbolic links, they can potentially be exploited to gain access to the host root filesystem.
IDs: CVE-2025-54867, GHSA-j26p-6wx7-f3pw
Record: https://patchnext.com/advisories/cve-2025-54867 (revision 1, source checked 26 Oct 2026, 15:39 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.0)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: youki 0.5.5. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io youki: affected < 0.5.5; fixed in 0.5.5

## Suggested inspection (read-only)
- crates.io youki: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on youki.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-j26p-6wx7-f3pw (GitHub-reviewed advisory GHSA-j26p-6wx7-f3pw lists affected ranges: crates.io youki >=0 <0.5.5)

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