CVE-2026-28684

MEDIUM6.6

python-dotenv: Symlink following in set_key allows arbitrary file overwrite via cross-device rename fallback

Published Apr 20, 2026

Modified 5 days ago

Details

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.

References

WEB

https://github.com/theskumar/python-dotenv/commit/790c5c02991100aa1bf41ee5330aca75edc51311

WEB

https://github.com/theskumar/python-dotenv/releases/tag/v1.2.2

DETECTION

https://github.com/theskumar/python-dotenv/security/advisories/GHSA-mf9w-mj56-hr94

ADVISORY

https://www.cve.org/CVERecord?id=CVE-2026-28684

CVSS Analysis

CVSS v3.1

6.6