Is CVE-2026-8328 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-8328 being exploited in the wild.

How severe is CVE-2026-8328?

Informational severity, with a CVSS score of 5.9, published 13 May 2026.

Which products and versions are affected?

Python Software Foundation CPython 3.10, 3.11, 3.12, 3.13, 3.14, 3.15, 3.12, 3.13, 3.14, 3.15.

Is there a fix for CVE-2026-8328?

A patch was published on 2026-05-10: Initial fix committed to CPython repository. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-8328 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-8328?

Check whether you run Python Software Foundation CPython at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-8328: Python CPython SSRF in ftplib.ftpcp function

CVE-2026-8328 · Severity: info · CVSS 5.9 · Published 2026-05-13

A vulnerability exists in the Python standard library's FTP module, which is used by developers to transfer files between servers. A malicious FTP server could trick a client into connecting to a different, unintended computer or service on the network. This could be used to bypass network security controls or perform unauthorized actions on internal systems.

Technologies: Python Software Foundation CPython. Vendors: Python Software Foundation.

Quick answers

Is CVE-2026-8328 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-8328 being exploited in the wild.
How severe is CVE-2026-8328?: Informational severity, with a CVSS score of 5.9, published 13 May 2026.
Which products and versions are affected?: Python Software Foundation CPython 3.10, 3.11, 3.12, 3.13, 3.14, 3.15, 3.12, 3.13, 3.14, 3.15.
Is there a fix for CVE-2026-8328?: A patch was published on 2026-05-10: Initial fix committed to CPython repository. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-8328 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-8328?: Check whether you run Python Software Foundation CPython at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The ftpcp() function in Lib/ftplib.py was found to be vulnerable to Server-Side Request Forgery (SSRF) because it calls parse227() directly and trusts the IP address provided by the source FTP server in response to a PASV command. This bypasses a previous fix (CVE-2021-4189) that was applied to the makepasv() function but missed in ftpcp(). An attacker controlling a malicious source FTP server can provide an arbitrary IP address and port, which the client then passes to the target server's PORT command, causing the target server to initiate a data connection to the attacker's chosen destination. The fix ensures ftpcp() uses the source server's actual peer address instead of the self-reported address.

Affected products

Python Software Foundation CPython 3.12, 3.13, 3.14, 3.15

Timeline

2026-05-10: patched: Initial fix committed to CPython repository.
2026-05-13: disclosed: CVE-2026-8328 published.

References

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