Summary
Apptainer ineffectively applies selinux and apparmor --security options
Workarounds
There are no known workarounds, other than to define system-wide apparmor / selinux policy for Apptainer itself. This would apply to all containers, not just those run with the --security flags, and could impact the operation of Apptainer itself.
References
Thanks to Sylabs for finding this issue, fixing it in https://github.com/sylabs/singularity/security/advisories/GHSA-wwrx-w7c9-rf87 which was easy to import into Apptainer, and disclosing it early to the Apptainer project for a coordinated release.
The related upstream runc disclosure which inspired the investigation is https://github.com/opencontainers/runc/security/advisories/GHSA-cgrx-mc8f-2prm.
Impact
In Apptainer versions less than 1.4.5, a container can disable two of the forms of the little used --security option, in particular the forms --security=apparmor:<profile> and --security=selinux:<label> which otherwise put restrictions on operations that containers can do. The --security option has always been mentioned in Apptainer documentation as being a feature for the root user, although these forms do also work for unprivileged users on systems where the corresponding feature is enabled. Apparmor is enabled by default on Debian-based distributions and SElinux is enabled by default on RHEL-based distributions, but on SUSE it depends on the distribution version.
In addition, a bug in the detection of selinux support in Apptainer's suid mode means that --security selinux:<label> flags may not be applied, even in the absence of an attack. In that case a warning message is emitted indicating that selinux is unavailable, but the warning may be may be overlooked, mis-interpreted, or not seen when apptainer is run from a script or other tool. Failure to apply requested restrictions should result in a fatal error rather than just a warning message.
CVE-2025-65105 has a CVSS score of 4.5 (Medium). The vector is requires local access, no privileges required, and user interaction required. 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 (1.4.5); 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.
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Ineffective write of selinux process labels is addressed via an update to the containers/selinux dependency in https://github.com/apptainer/apptainer/pull/3226. That update brings in the upstream fix for https://github.com/advisories/GHSA-cgrx-mc8f-2prm which was for a different but related vulnerability.
Ineffective write of apparmor process profiles is addressed in commit 4313b42.
Failure to detect apparmor / selinux support, when --security flags are provided, is made an error rather than a warning in commit 82f1790.
Frequently Asked Questions
- What is CVE-2025-65105? CVE-2025-65105 is a medium-severity security vulnerability in github.com/apptainer/apptainer (go), affecting versions < 1.4.5. It is fixed in 1.4.5.
- How severe is CVE-2025-65105? CVE-2025-65105 has a CVSS score of 4.5 (Medium). 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 github.com/apptainer/apptainer are affected by CVE-2025-65105? github.com/apptainer/apptainer (go) versions < 1.4.5 is affected.
- Is there a fix for CVE-2025-65105? Yes. CVE-2025-65105 is fixed in 1.4.5. Upgrade to this version or later.
- Is CVE-2025-65105 exploitable, and should I be worried? Whether CVE-2025-65105 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-2025-65105 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-2025-65105? Upgrade
github.com/apptainer/apptainerto 1.4.5 or later.