CVE-2026-115506
Received Received - Intake

XML Billion Laughs DoS in libexpat

Vulnerability report for CVE-2026-115506, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.

Publication date: 2026-10-22

Last updated on: 2026-10-22

Assigner: VulnCheck

Description

libexpat through 2.9.0 contains a denial of service vulnerability because billion laughs protection in accountingDiffTolerated() in xmlparse.c detects entity amplification too late. Attackers can supply a moderately sized XML document with a large DTD and nested entity expansions to consume tens of seconds of CPU per parse.

CVSS Scores

EPSS Scores

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Meta Information

Published
2026-10-22
Last Modified
2026-10-22
Generated
2026-10-23
EPSS Evaluated
N/A
NVD

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
libexpat libexpat 0

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-776 The product uses XML documents and allows their structure to be defined with a Document Type Definition (DTD), but it does not properly control the number of recursive definitions of entities.

Attack-Flow Graph

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EPSS Chart