CVE-2026-28684
python-dotenv: Symlink following in set_key allows arbitrary file overwrite via cross-device rename fallback
Description
python-dotenv reads key-value pairs from a .env file and can set them as environment variables. Prior to version 1.2.2, `set_key()` and `unset_key()` in python-dotenv follow symbolic links when rewriting `.env` files, allowing a local attacker to overwrite arbitrary files via a crafted symlink when a cross-device rename fallback is triggered. Users should upgrade to v.1.2.2 or, as a workaround, apply the patch manually.
INFO
Published Date :
April 20, 2026, 5:16 p.m.
Last Modified :
April 27, 2026, 1:44 p.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Upgrade python-dotenv to version 1.2.2.
- Apply the vendor patch manually.
- Avoid using symbolic links with .env files.
Public PoC/Exploit Available at Github
CVE-2026-28684 has a 4 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-28684.
| URL | Resource |
|---|---|
| https://github.com/theskumar/python-dotenv/commit/790c5c02991100aa1bf41ee5330aca75edc51311 | Patch |
| https://github.com/theskumar/python-dotenv/releases/tag/v1.2.2 | Release Notes |
| https://github.com/theskumar/python-dotenv/security/advisories/GHSA-mf9w-mj56-hr94 | Exploit Patch Vendor Advisory |
| https://github.com/theskumar/python-dotenv/security/advisories/GHSA-mf9w-mj56-hr94 | Exploit Patch Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-28684 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-28684
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
NotebookLM MCP CLI - Access NotebookLM via Claude with security fixes and FastMCP 1.0 compatibility
Python
Make AI agents and AI workflows measurably reliable. Epistemic measurement, Noetic RAG, Sentinel gating, and grounded calibration for Claude Code and beyond
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Makefile Python Shell Dockerfile PowerShell Ruby
MVidarr - The Music Video Management System
HTML Python Shell JavaScript CSS TypeScript Batchfile Dockerfile Mako Go Template
This software will connect to a pub/sub broker used by Chirpstack, subscribe to the device message topic and forward this message to a Azure IoT Hub.
Python Shell Dockerfile
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-28684 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-28684 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Apr. 27, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:saurabh-kumar:python-dotenv:*:*:*:*:*:python:*:* versions up to (excluding) 1.2.2 Added Reference Type GitHub, Inc.: https://github.com/theskumar/python-dotenv/commit/790c5c02991100aa1bf41ee5330aca75edc51311 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/theskumar/python-dotenv/releases/tag/v1.2.2 Types: Release Notes Added Reference Type CISA-ADP: https://github.com/theskumar/python-dotenv/security/advisories/GHSA-mf9w-mj56-hr94 Types: Exploit, Patch, Vendor Advisory Added Reference Type GitHub, Inc.: https://github.com/theskumar/python-dotenv/security/advisories/GHSA-mf9w-mj56-hr94 Types: Exploit, Patch, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Apr. 20, 2026
Action Type Old Value New Value Added Reference https://github.com/theskumar/python-dotenv/security/advisories/GHSA-mf9w-mj56-hr94 -
New CVE Received by [email protected]
Apr. 20, 2026
Action Type Old Value New Value Added Description python-dotenv reads key-value pairs from a .env file and can set them as environment variables. Prior to version 1.2.2, `set_key()` and `unset_key()` in python-dotenv follow symbolic links when rewriting `.env` files, allowing a local attacker to overwrite arbitrary files via a crafted symlink when a cross-device rename fallback is triggered. Users should upgrade to v.1.2.2 or, as a workaround, apply the patch manually. Added CVSS V3.1 AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:H Added CWE CWE-59 Added CWE CWE-61 Added Reference https://github.com/theskumar/python-dotenv/commit/790c5c02991100aa1bf41ee5330aca75edc51311 Added Reference https://github.com/theskumar/python-dotenv/releases/tag/v1.2.2 Added Reference https://github.com/theskumar/python-dotenv/security/advisories/GHSA-mf9w-mj56-hr94