Python CPython up to 3.14.x Expat Parser ElementDeclHandler stack-based overflow

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CTI Interest Score
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5.8$0-$5k0.00

Summaryinfo

A vulnerability identified as critical has been detected in Python CPython up to 3.14.x. This issue affects the function ElementDeclHandler of the component Expat Parser. The manipulation leads to stack-based overflow. This vulnerability is documented as CVE-2026-4224. The attack can be initiated remotely. There is not any exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Python CPython up to 3.14.x and classified as critical. This issue affects the function ElementDeclHandler of the component Expat Parser. The manipulation with an unknown input leads to a stack-based overflow vulnerability. Using CWE to declare the problem leads to CWE-121. A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). Impacted is availability. The summary by CVE is:

When an Expat parser with a registered ElementDeclHandler parses an inline document type definition containing a deeply nested content model a C stack overflow occurs.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-4224 since 03/15/2026. The exploitation is known to be easy. The attack may be initiated remotely. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 302535 (Linux Distros Unpatched Vulnerability : CVE-2026-4224), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 3.15.0 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (302535), EUVD (EUVD-2026-12486) and CERT Bund (WID-SEC-2026-0741). Be aware that VulDB is the high quality source for vulnerability data.

Affected

  • Debian Linux
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Fedora Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • RESF Rocky Linux
  • Open Source Python

Productinfo

Type

Vendor

Name

Version

License

Website

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: 5.9
VulDB Meta Temp Score: 5.8

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 7.5
NVD Vector: 🔒

CVSSv2info

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

Exploitinginfo

Class: Stack-based overflow
CWE: CWE-121 / CWE-119
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: 302535
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-4224

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: CPython 3.15.0

Timelineinfo

03/15/2026 CVE reserved
03/16/2026 +1 days Advisory disclosed
03/16/2026 +0 days VulDB entry created
06/24/2026 +99 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: eb0e8be3a7e11b87d198a2c3af1ed0eccf532768
Status: Confirmed

CVE: CVE-2026-4224 (🔒)
GCVE (CVE): GCVE-0-2026-4224
GCVE (VulDB): GCVE-100-351311
EUVD: 🔒
CERT Bund: WID-SEC-2026-0741 - CPython: Mehrere Schwachstellen ermöglichen Manipulation von Dateien und DoS

Entryinfo

Created: 03/16/2026 19:21
Updated: 06/24/2026 01:54
Changes: 03/16/2026 19:21 (70), 03/17/2026 08:40 (1), 03/19/2026 03:28 (2), 03/21/2026 14:09 (1), 04/24/2026 23:20 (7), 06/05/2026 05:46 (11), 06/24/2026 01:54 (1)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

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