VDB-356919 · CVE-2026-3446 · EUVD-2026-21545

Python CPython up to 3.13.12/3.14.3/3.15.0a7 b64decode

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3.0	$0-$5k	0.00

Summaryinfo

A vulnerability has been found in Python CPython up to 3.13.12/3.14.3/3.15.0a7 and classified as problematic. This affects the function b64decode. Performing a manipulation results in an unknown weakness. This vulnerability is cataloged as CVE-2026-3446. It is possible to initiate the attack remotely. There is no exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Python CPython up to 3.13.12/3.14.3/3.15.0a7. It has been classified as problematic. This is going to have an impact on integrity. The summary by CVE is:

When calling base64.b64decode() or related functions the decoding process would stop after encountering the first padded quad regardless of whether there was more information to be processed. This can lead to data being accepted which may be processed differently by other implementations. Use "validate=True" to enable stricter processing of base64 data.

It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2026-3446 since 03/02/2026. The exploitability is told to be difficult. It is possible to initiate the attack remotely. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 306042 (Linux Distros Unpatched Vulnerability : CVE-2026-3446), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 3.13.13, 3.14.4 or 3.15.0a8 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (306042), EUVD (EUVD-2026-21545) and CERT Bund (WID-SEC-2026-1064). Be aware that VulDB is the high quality source for vulnerability data.

Affected

Red Hat Enterprise Linux
Fedora Linux
SUSE Linux
Oracle Linux
SUSE openSUSE
RESF Rocky Linux
Open Source Python

Productinfo

Type

Programming Language Software

Vendor

Python

Name

CPython

Version

License

open-source

Website

Product: https://github.com/python/cpython/

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: 3.1
VulDB Meta Temp Score: 3.0

VulDB Base Score: 3.1
VulDB Temp Score: 3.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Unknown
CWE: Unknown
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 306042
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-3446

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: CPython 3.13.13/3.14.4/3.15.0a8

Timelineinfo

03/02/2026 CVE reserved
04/10/2026 +38 days Advisory disclosed
04/10/2026 +0 days VulDB entry created
06/23/2026 +74 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-3446 (🔒)
GCVE (CVE): GCVE-0-2026-3446
GCVE (VulDB): GCVE-100-356919
EUVD: 🔒
CERT Bund: WID-SEC-2026-1064 - CPython: Mehrere Schwachstellen

Entryinfo

Created: 04/10/2026 20:40
Updated: 06/23/2026 19:18
Changes: 04/10/2026 20:40 (66), 04/12/2026 16:12 (1), 04/13/2026 03:06 (2), 04/13/2026 22:00 (7), 04/22/2026 02:15 (1), 04/24/2026 23:20 (1), 06/23/2026 19:18 (1)
Complete: 🔍
Cache ID: 216::103