CVE-2026-8328

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.

• CWE-918

• https://github.com/python/cpython/commit/5dadc64673ce875ebfb24163907777dae0f6ca06
• https://github.com/python/cpython/commit/7d95a1dc7382b55cba7fdd6a110336077584a4f0
• https://github.com/python/cpython/commit/bb3446dda6c49b32e67c11dbbbf221b40be00763
• https://github.com/python/cpython/commit/c88704431ea3248ca769384c13856330976fac1d
• https://github.com/python/cpython/commit/eac4fe3b2c77693790a5ef7dfab127c1fee81bf9
• https://github.com/python/cpython/issues/87451
• https://github.com/python/cpython/pull/149648
• https://mail.python.org/archives/list/security-announce@python.org/thread/ITF2BAPBQEPYK3LDMPRSY435JGNHYNDP/

Published

May 13, 2026

Last Modified

Jun 17, 2026

Status

Awaiting Analysis