Summary
It was discovered that the ld.so.cache in images generated by apko had file system permissions mode 0666:
bash-5.3# find / -type f -perm -o+w
/etc/ld.so.cache
This issue was introduced in commit 04f37e2 ("generate /etc/ld.so.cache (#1629)")(v0.27.0).
Acknowledgements
Many thanks to Cody Harris from H2O.ai for reporting this issue.
Impact
This potentially allows a local unprivileged user to add additional additional directories including dynamic libraries to the dynamic loader path. A user could exploit this by placing a malicious library in a directory they control.
CVE-2025-53945 has a CVSS score of 7.0 (High). The vector is requires local access, low 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 (0.29.5); 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
This issue was addressed in apko in aedb077 ("fix: /etc/ld.so.cache file permissions (#1758)") (v0.29.5).
Frequently Asked Questions
- What is CVE-2025-53945? CVE-2025-53945 is a high-severity security vulnerability in chainguard.dev/apko (go), affecting versions >= 0.27.0, < 0.29.5. It is fixed in 0.29.5.
- How severe is CVE-2025-53945? CVE-2025-53945 has a CVSS score of 7.0 (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 chainguard.dev/apko are affected by CVE-2025-53945? chainguard.dev/apko (go) versions >= 0.27.0, < 0.29.5 is affected.
- Is there a fix for CVE-2025-53945? Yes. CVE-2025-53945 is fixed in 0.29.5. Upgrade to this version or later.
- Is CVE-2025-53945 exploitable, and should I be worried? Whether CVE-2025-53945 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-2025-53945 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-2025-53945? Upgrade
chainguard.dev/apkoto 0.29.5 or later.