Summary
youki container escape and denial of service due to arbitrary write gadgets and procfs write redirects
Full technical description
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 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.
Impact
CVE-2025-62596 has a CVSS score of 10.0 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.5.7); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2025-62596? CVE-2025-62596 is a high-severity security vulnerability in youki (rust), affecting versions < 0.5.7. It is fixed in 0.5.7.
- How severe is CVE-2025-62596? CVE-2025-62596 has a CVSS score of 10.0 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of youki are affected by CVE-2025-62596? youki (rust) versions < 0.5.7 is affected.
- Is there a fix for CVE-2025-62596? Yes. CVE-2025-62596 is fixed in 0.5.7. Upgrade to this version or later.
- Is CVE-2025-62596 exploitable, and should I be worried? Whether CVE-2025-62596 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2025-62596 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2025-62596? Upgrade
youkito 0.5.7 or later.