CVE-2026-8328

MEDIUM

FTP PASV SSRF, ftpcp() does not use actual peer address, trusts server-supplied PASV host address

Title source: cna
STIX 2.1

Description

The ftpcp() function in Lib/ftplib.py was not updated when CVE-2021-4189 was fixed. While makepasv() was patched to replace server-supplied PASV host addresses with the actual peer address (getpeername()[0]), ftpcp() still calls parse227() directly and passes the raw attacker-controllable IP address and port to target.sendport(). This patch is related to CVE-2021-4189.

References (8)

Core 8
Core References
Issue Tracking issue-tracking
https://github.com/python/cpython/issues/87451

Scores

CVSS v4 5.9
EPSS 0.0040
EPSS Percentile 31.7%
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-918
Status published
Products (4)
Python Software Foundation/CPython < 3.13.14
Python Software Foundation/CPython < 3.15.0
Python Software Foundation/CPython 3.14.0 - 3.14.6
Python Software Foundation/CPython 3.15.0a1 - 3.15.0b2
Published May 13, 2026
Tracked Since May 14, 2026