Low 1.8Published Oct 31, 2025

CVE-2025-6075Quadratic complexity in os.path.expandvars() with user-controlled template

Updated under an hour ago (Oct 28, 2026, 4:00 PM ET)

Does this affect you?

It affects Python Software Foundation CPython and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

Do this next

Start free and add your stack

Free account, 1 product

Every CVE for Python Software Foundation CPython

Exploited in the last 30 days

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

CVSS: 1.8 LOW (v4.0, CNA)CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
Weakness (CWE): CWE-400
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: PSF
NVD analysis: Analyzed
Record last updated: Jul 31, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Python Software Foundation CPython python_software_foundation:cpython (from the name)	before 3.9.25; from 3.10.0 before 3.10.20; from 3.11.0 before 3.11.15; from 3.12.0 before 3.12.13; from 3.13.0 before 3.13.10; from 3.14.0 before 3.14.1; from 3.15.0a1 before 3.15.0a2	CNA record
python python python:python	before 3.9.0; from 3.13.1 before 3.13.11; from 3.14.0 before 3.14.1; 3.15.0	NVD

References

References

https://github.com/python/cpython/issues/136065	issue-tracking, vendor-advisory
https://mail.python.org/archives/list/security-announce@python.org/thread/IUP5QJ6D4KK6ULHOMPC7DPNKRYQTQNLA/	vendor-advisory, third-party-advisory
https://github.com/python/cpython/commit/2e6150adccaaf5bd95d4c19dfd04a36e0b325d8c	patch
https://github.com/python/cpython/commit/631ba3407e3348ccd56ce5160c4fb2c5dc5f4d84	patch
https://github.com/python/cpython/commit/892747b4cf0f95ba8beb51c0d0658bfaa381ebca	patch
https://github.com/python/cpython/commit/9ab89c026aa9611c4b0b67c288b8303a480fe742	patch
https://github.com/python/cpython/commit/c8a5f3435c342964e0a432cc9fb448b7dbecd1ba	patch
https://github.com/python/cpython/commit/f029e8db626ddc6e3a3beea4eff511a71aaceb5c	patch
https://github.com/python/cpython/commit/5dceb93486176e6b4a6d9754491005113eb23427	patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.