Summary
Apptainer has incorrect path matching for 'limit container paths' directive
Workarounds
If developers do not use setuid mode or do not use the limit container paths functionality, then this issue does not affect their installation. Note that, as documented [1], if user namespaces are allowed for unrestricted use then this functionality does not stop users from running any container of their choice.
If developers do use the limit container paths functionality they are advised to update.
Credit
This vulnerability was discovered and disclosed to the Apptainer project by Dave Trudgian of Sylabs.
Resources
[1] https://apptainer.org/docs/admin/latest/configfiles.html#limiting-container-execution
Impact
The limit container paths directive in apptainer.conf is intended to allow a system administrator limit the paths from which containers can be run, under setuid mode. Due to incorrect matching of a path string, sibling directories with similar names may incorrectly be allowed.
For example, the configuration:
limit container paths = /data/safe
Will also allow containers in /data/safe-but-unsafe to be run.
Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.
CVE-2026-48785 has a CVSS score of 4.8 (Medium). The vector is requires local access, low 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 (1.5.1); 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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The issue is patched in apptainer version 1.5.1.
Frequently Asked Questions
- What is CVE-2026-48785? CVE-2026-48785 is a medium-severity path traversal vulnerability in github.com/apptainer/apptainer (go), affecting versions < 1.5.1. It is fixed in 1.5.1. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
- How severe is CVE-2026-48785? CVE-2026-48785 has a CVSS score of 4.8 (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-2026-48785? github.com/apptainer/apptainer (go) versions < 1.5.1 is affected.
- Is there a fix for CVE-2026-48785? Yes. CVE-2026-48785 is fixed in 1.5.1. Upgrade to this version or later.
- Is CVE-2026-48785 exploitable, and should I be worried? Whether CVE-2026-48785 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-2026-48785 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-2026-48785? Upgrade
github.com/apptainer/apptainerto 1.5.1 or later.