---
id: CVE-2026-76956
title: >-
  In libexpat 2.8.2 and 2.8.3 before 2.8.4, misinterpretation of getentropy's
  return code leads to insufficient entropy, which results in being vulnerable
  to hash flooding attacks, causing a denial of service via crafted XML content.
summary: >-
  In libexpat 2.8.2 and 2.8.3 before 2.8.4, misinterpretation of getentropy's
  return code leads to insufficient entropy, which results in being vulnerable
  to hash flooding attacks, causing a denial of service via crafted XML content.
severity: medium
cvss: 5.9
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-394
  - CWE-331
vendor: libexpat_project
product: libexpat
affected:
  - 'libexpat >= 2.8.2, < 2.8.4'
patched:
  - libexpat 2.8.4
published: '2026-08-20'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T21:08:20.697'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-76956'
references:
  - url: 'https://github.com/libexpat/libexpat/pull/1326'
    label: cve@mitre.org
  - url: 'https://github.com/libexpat/libexpat/pull/1329'
    label: cve@mitre.org
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-76956.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-76956'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2520124'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-76956'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-76956'
  - url: 'https://access.redhat.com/errata/RHSA-2026:60451'
tags:
  - nvd
  - csaf
  - vex
  - red-hat
epss: 0.00452
epssPercentile: 0.36544
ingestedAt: '2026-09-08T21:11:12.284Z'
---

## Overview

In libexpat 2.8.2 and 2.8.3 before 2.8.4, misinterpretation of getentropy's return code leads to insufficient entropy, which results in being vulnerable to hash flooding attacks, causing a denial of service via crafted XML content.

## Affected

- `libexpat >= 2.8.2, < 2.8.4`

## Remediation

Upgrade past the affected range:

- `libexpat 2.8.4`

## Vendor advisories

- **RHSA-2026:60451** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-08-27 · [advisory](https://access.redhat.com/errata/RHSA-2026:60451)