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
Thanks to Li Fubang (@lifubang from acmcoder.com, CIIC) and Tõnis Tiigi (@tonistiigi from Docker) for both independently discovering runc's original vulnerability, as well as Aleksa Sarai (@cyphar from SUSE) for the original research into this class of security issues and solutions.
| Score | Percentile |
|---|---|
| 0.05% | 14.71% |
| Base score | Version | Severity | Vector |
|---|---|---|---|
| 10.0 | 3.1 | — |
|
| 7.3 | 4.0 | — |
|
| Type | Value |
|---|---|
| GHSA | GHSA-vf95-55w6-qmrf ↗ |
| CVE | CVE-2025-62596 ↗ |
Vulnerable version ranges and first patched releases as published by GitHub.
| Ecosystem | Package | Vulnerable range | First patched | Vulnerable functions |
|---|---|---|---|---|
| rust | youki | < 0.5.7 | 0.5.7 | — |