---
id: CVE-2025-6075
title: |-
  If the value passed to os.path.expandvars() is user-controlled a 
  performance degradation is possible when expanding environment 
  variables.
summary: |-
  If the value passed to os.path.expandvars() is user-controlled a 
  performance degradation is possible when expanding environment 
  variables.
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-400
vendor: python
product: python
affected:
  - python < 3.9.0
  - 'python >= 3.13.1, < 3.13.11'
  - 'python >= 3.14.0, < 3.14.1'
  - python = 3.15.0
patched:
  - python 3.14.1
published: '2025-10-31'
updated: '2026-07-30'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-6075'
references:
  - url: >-
      https://github.com/python/cpython/commit/2e6150adccaaf5bd95d4c19dfd04a36e0b325d8c
    label: cna@python.org
  - url: >-
      https://github.com/python/cpython/commit/5dceb93486176e6b4a6d9754491005113eb23427
    label: cna@python.org
  - url: >-
      https://github.com/python/cpython/commit/631ba3407e3348ccd56ce5160c4fb2c5dc5f4d84
    label: cna@python.org
  - url: >-
      https://github.com/python/cpython/commit/892747b4cf0f95ba8beb51c0d0658bfaa381ebca
    label: cna@python.org
  - url: >-
      https://github.com/python/cpython/commit/9ab89c026aa9611c4b0b67c288b8303a480fe742
    label: cna@python.org
  - url: >-
      https://github.com/python/cpython/commit/c8a5f3435c342964e0a432cc9fb448b7dbecd1ba
    label: cna@python.org
  - url: >-
      https://github.com/python/cpython/commit/f029e8db626ddc6e3a3beea4eff511a71aaceb5c
    label: cna@python.org
  - url: 'https://github.com/python/cpython/issues/136065'
    label: cna@python.org
  - url: >-
      https://mail.python.org/archives/list/security-announce@python.org/thread/IUP5QJ6D4KK6ULHOMPC7DPNKRYQTQNLA/
    label: cna@python.org
tags:
  - nvd
epss: 0.00139
epssPercentile: 0.02686
ingestedAt: '2026-07-31T06:58:51.061Z'
---

## Overview

If the value passed to os.path.expandvars() is user-controlled a 
performance degradation is possible when expanding environment 
variables.

## Affected

- `python < 3.9.0`
- `python >= 3.13.1, < 3.13.11`
- `python >= 3.14.0, < 3.14.1`
- `python = 3.15.0`

## Remediation

Upgrade past the affected range:

- `python 3.14.1`