CVE-2026-8328Network attack vectorHinoki check available

SSRF via trusted PASV host in ftpcp

Published May 13, 2026 · Updated May 13, 2026

SSRF in CPython ftplib before 3.10.21, 3.11.16, 3.12.14, 3.13.14, 3.14.6, and 3.15.0b2 allows remote attackers to redirect FTP traffic. The ftpcp() function passes the source server's self-reported PASV IPv4 address and port directly to target.sendport() instead of using the connected peer address. Exploitation requires code to call ftpcp() with a malicious source FTP server and a target FTP server, which then opens its data connection to an attacker-chosen host and port.

CVSS severity5.9
Medium
EPSS probability0.46%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

SSRF in CPython ftplib before 3.10.21, 3.11.16, 3.12.14, 3.13.14, 3.14.6, and 3.15.0b2 allows remote attackers to redirect FTP traffic. The ftpcp() function passes the source server's self-reported PASV IPv4 address and port directly to target.sendport() instead of using the connected peer address. Exploitation requires code to call ftpcp() with a malicious source FTP server and a target FTP server, which then opens its data connection to an attacker-chosen host and port.

The record

CVE
CVE-2026-8328
Published
May 13, 2026
Updated
May 13, 2026
Vendor
Python Software Foundation
Product
CPython
Classifications
CWE-918, T1090
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 13, 2026CVE publishedPublication date reported by the CVE source.
  2. May 13, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <3.15.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Python Software Foundation · CPythonversion=0 <3.15.0

Published CVSS scores

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

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-918Server-Side Request Forgery (SSRF)
T1090Proxy

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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