Pyenv up to 2.7.x Version File Reader pyenv-version-file-read is_version_safe os command injection

Summaryinfo

A vulnerability identified as problematic has been detected in Pyenv up to 2.7.x. Affected by this vulnerability is the function is_version_safe of the file libexec/pyenv-version-file-read of the component Version File Reader. Performing a manipulation results in os command injection. This vulnerability was named CVE-2026-68939. The attack needs to be approached locally. There is no available exploit.

Detailsinfo

A vulnerability classified as problematic has been found in Pyenv up to 2.7.x. This affects the function is_version_safe of the file libexec/pyenv-version-file-read of the component Version File Reader. The manipulation with an unknown input leads to a os command injection vulnerability. CWE is classifying the issue as CWE-78. The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component. This is going to have an impact on integrity, and availability. The summary by CVE is:

Pyenv provides simple Python version management. Prior to 2.8.0, is_version_safe() in libexec/pyenv-version-file-read accepts shell glob metacharacters in .python-version values, and unquoted PYENV_VERSION expansion in libexec/pyenv-version-name, libexec/pyenv-which, libexec/pyenv-prefix, libexec/pyenv-local, libexec/pyenv-global, libexec/pyenv-version, and libexec/pyenv-versions pathname-expands the value against the current directory, allowing a matching attacker-controlled file to silently select a different installed interpreter or version. This issue is fixed in version 2.8.0.

It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2026-68939 since 07/31/2026. The exploitability is told to be easy. Attacking locally is a requirement. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1202 according to MITRE ATT&CK.

Upgrading to version 2.8.0 eliminates this vulnerability.

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Productinfo

Name

• Pyenv

Version

• 2.0
• 2.1
• 2.2
• 2.3
• 2.4
• 2.5
• 2.6
• 2.7

Website

• Product: https://github.com/pyenv/pyenv/

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