youki container escape and denial of service due to arbitrary write gadgets and procfs write redirects

Exploitation

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

CVSS 4.0

7.3 · CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H · score source

EPSS

• CVE-2025-62596: 0.27% estimated exploitation activity in the next 30 days; percentile 18.91 (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.

Impact

youki’s apparmor handling performs insufficiently strict write-target validation, which—combined with path substitution during pathname resolution—can allow writes to unintended procfs locations. Weak write-target check youki only verifies that the destination lies somewhere under procfs. As a result, a write intended for /proc/self/attr/apparmor/exec can succeed even if the path has been redirected to /proc/sys/kernel/hostname(which is also in procfs). Path substitution While resolving a path component-by-component, a shared-mount race can substitute intermediate components and redirect the final target. This is a different project, but the core logic is similar to the CVE in runc. Issues were identified in runc, and verification was also conducted in youki to confirm the problems. https://github.com/opencontainers/runc/security/advisories/GHSA-cgrx-mc8f-2prm Credits

Thanks to Li Fubang (@lifubang from acmcoder.com, CIIC) and Tõnis Tiigi (@tonistiigi from Docker) for…

Published by the source

5 Nov 2025, 18:45 UTC

Last modified by the source

15 Nov 2025, 02:25 UTC

Source last checked

26 Oct 2026, 15:39 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-vf95-55w6-qmrf

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# Patch Next advisory brief: CVE-2025-62596

Advisory: youki container escape and denial of service due to arbitrary write gadgets and procfs write redirects
IDs: CVE-2025-62596, GHSA-vf95-55w6-qmrf
Record: https://patchnext.com/advisories/cve-2025-62596 (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 7.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: youki 0.5.7. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io youki: affected < 0.5.7; fixed in 0.5.7

## 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-vf95-55w6-qmrf (GitHub-reviewed advisory GHSA-vf95-55w6-qmrf lists affected ranges: crates.io youki >=0 <0.5.7)

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