libexpat up to 2.7.3 doContent integer overflow

CVSS Meta Temp Score
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CTI Interest Score
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6.3$0-$5k0.00

Summaryinfo

A vulnerability described as problematic has been identified in libexpat up to 2.7.3. Affected is the function doContent. Executing a manipulation can lead to integer overflow. The identification of this vulnerability is CVE-2026-25210. The attack can only be executed locally. There is no exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in libexpat up to 2.7.3. It has been declared as problematic. This vulnerability affects the function doContent. The manipulation with an unknown input leads to a integer overflow vulnerability. The CWE definition for the vulnerability is CWE-190. The product performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

In libexpat before 2.7.4, the doContent function does not properly determine the buffer size bufSize because there is no integer overflow check for tag buffer reallocation.

The advisory is available at github.com. This vulnerability was named CVE-2026-25210 since 01/30/2026. The exploitation appears to be difficult. Local access is required to approach this attack. Technical details are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 297227 (Linux Distros Unpatched Vulnerability : CVE-2026-25210), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 2.7.4 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 (297227), EUVD (EUVD-2026-6141) and CERT Bund (WID-SEC-2026-0265). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

  • Open Source expat

Productinfo

Name

Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.4
VulDB Meta Temp Score: 6.3

VulDB Base Score: 4.5
VulDB Temp Score: 4.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 7.8
NVD Vector: 🔒

CNA Base Score: 6.9
CNA Vector (MITRE): 🔒

CVSSv2info

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

Exploitinginfo

Class: Integer overflow
CWE: CWE-190 / CWE-189
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 297227
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-25210

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: libexpat 2.7.4
Patch: github.com

Timelineinfo

01/30/2026 Advisory disclosed
01/30/2026 +0 days CVE reserved
01/30/2026 +0 days VulDB entry created
03/11/2026 +40 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-25210 (🔒)
GCVE (CVE): GCVE-0-2026-25210
GCVE (VulDB): GCVE-100-343474
EUVD: 🔒
CERT Bund: WID-SEC-2026-0265 - expat: Schwachstelle ermöglicht Codeausführung

Entryinfo

Created: 01/30/2026 08:22
Updated: 03/11/2026 01:16
Changes: 01/30/2026 08:22 (63), 01/30/2026 12:32 (7), 01/31/2026 01:26 (2), 02/05/2026 06:07 (1), 02/19/2026 19:04 (1), 03/11/2026 01:16 (11)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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