---
id: CVE-2024-45490
title: An issue was discovered in libexpat before 2.6.3
summary: >-
  An issue was discovered in libexpat before 2.6.3. xmlparse.c does not reject a
  negative length for XML_ParseBuffer.
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cvssSource: adp
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2024-08-30T18:17:03.200505Z'
published: '2024-08-30'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T00:50:04.079Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2024-45490'
references:
  - url: 'https://github.com/libexpat/libexpat/pull/890'
  - url: 'https://github.com/libexpat/libexpat/issues/887'
tags:
  - cve.org
  - exploit-available
epss: 0.01686
epssPercentile: 0.76901
ingestedAt: '2026-10-15T04:46:37.330Z'
exploits:
  github: 1
  githubRepos:
    - 'https://github.com/jstjep00/CVE-2024-45490-libexpat-poc'
  checkedAt: '2026-10-27T16:42:38.474Z'
exploitAvailable: true
---

## Overview

An issue was discovered in libexpat before 2.6.3. xmlparse.c does not reject a negative length for XML_ParseBuffer.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.