CVE-2026-56407
libexpat Integer Overflow
Description
libexpat before 2.8.2 has an integer overflow in doProlog that is related to storeEntityValue and entity textLen.
INFO
Published Date :
June 21, 2026, 4:16 p.m.
Last Modified :
June 23, 2026, 4:28 p.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | 8254265b-2729-46b6-b9e3-3dfca2d5bfca | ||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update libexpat to version 2.8.2 or newer.
- Apply relevant security patches promptly.
- Recompile applications using the updated library.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-56407.
| URL | Resource |
|---|---|
| https://github.com/libexpat/libexpat/pull/1262 | Patch Issue Tracking |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-56407 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-56407
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-56407 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-56407 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jun. 23, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:libexpat_project:libexpat:*:*:*:*:*:*:*:* versions up to (excluding) 2.8.2 Added Reference Type MITRE: https://github.com/libexpat/libexpat/pull/1262 Types: Issue Tracking, Patch -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 22, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-56407', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-06-22T15:54:56.617975Z'} -
New CVE Received by [email protected]
Jun. 21, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'libexpat project', 'product': 'libexpat', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '2.8.2', 'versionType': 'semver'}], 'defaultStatus': 'unaffected'}] Added Description libexpat before 2.8.2 has an integer overflow in doProlog that is related to storeEntityValue and entity textLen. Added CVSS V3.1 AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L Added CWE CWE-190 Added Reference https://github.com/libexpat/libexpat/pull/1262