SB2026032435 - Multiple DoS vulnerabilities in libexpat



SB2026032435 - Multiple DoS vulnerabilities in libexpat

Published: March 24, 2026

Security Bulletin ID SB2026032435
Severity
Medium
Patch available
YES
Number of vulnerabilities 3
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 67% Low 33%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 3 secuirty vulnerabilities.


1) NULL pointer dereference (CVE-ID: CVE-2026-32778)

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to a NULL pointer dereference in the function setContext in libexpat when processing XML input under low-memory conditions. A remote attacker can send a specially crafted XML file to cause a denial of service.

Exploitation requires repeated processing of malicious input following an initial out-of-memory condition.


2) Infinite loop (CVE-ID: CVE-2026-32777)

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to an infinite loop in the DTD content parser when processing a specially crafted XML file. A remote attacker can send a specially crafted request to cause a denial of service.


3) NULL Pointer Dereference (CVE-ID: CVE-2026-32776)

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to a NULL pointer dereference in the XML parser when processing malicious XML content with empty external parameter entity content. A remote attacker can send a specially crafted XML file to cause a denial of service.


Remediation

Install update from vendor's website.