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.

CVSS 4.0

5.9CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

EPSS

0.5% chance of exploitation in the next 30 days; higher than 39% of CVEs (scores of 2026-10-25)

CWE

CWE-918

Published

2026-05-13

Modified

2026-10-26

Record from

the NVD, synced 2026-10-26

References

• https://github.com/python/cpython/commit/2bbcf3fb7a420a05605576c0f9468d4675381b5f
• 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

Check your stackJSON