Python CPython up to 3.14.x Lib/ftplib.py ftpcp server-side request forgery

CVSS Meta Temp Score
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CTI Interest Score
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7.0$0-$5k0.00

Summaryinfo

A vulnerability was found in Python CPython up to 3.14.x. It has been rated as critical. This issue affects the function ftpcp in the library Lib/ftplib.py. Performing a manipulation results in server-side request forgery. This vulnerability is identified as CVE-2026-8328. The attack can be initiated remotely. There is not any exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Python CPython up to 3.14.x. It has been classified as critical. This affects the function ftpcp in the library Lib/ftplib.py. The manipulation with an unknown input leads to a server-side request forgery vulnerability. CWE is classifying the issue as CWE-918. The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-8328 since 05/11/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 325428 (Ubuntu 22.04 LTS / 24.04 LTS / 26.04 LTS : Python vulnerabilities (USN-8509-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 3.15.0 eliminates this vulnerability. Applying a patch is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (325428), EUVD (EUVD-2026-30177) and CERT Bund (WID-SEC-2026-1520). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

  • Open Source Python

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 7.3
VulDB Meta Temp Score: 7.0

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Server-side request forgery
CWE: CWE-918
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 325428
Nessus Name: Ubuntu 22.04 LTS / 24.04 LTS / 26.04 LTS : Python vulnerabilities (USN-8509-1)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: CPython 3.15.0
Patch: github.com

Timelineinfo

05/11/2026 CVE reserved
05/14/2026 +3 days Advisory disclosed
05/14/2026 +0 days VulDB entry created
08/13/2026 +91 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: 87451
Status: Confirmed

CVE: CVE-2026-8328 (🔒)
GCVE (CVE): GCVE-0-2026-8328
GCVE (VulDB): GCVE-100-363741
EUVD: 🔒
CERT Bund: WID-SEC-2026-1520 - CPython: Schwachstelle ermöglicht Manipulation von Daten

Entryinfo

Created: 05/14/2026 05:39
Updated: 08/13/2026 04:36
Changes: 05/14/2026 05:39 (71), 05/15/2026 07:23 (7), 07/08/2026 00:33 (2), 08/13/2026 04:36 (2)
Complete: 🔍
Cache ID: 216::103

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