CVE-2026-115506

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 v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/hannob/lololol
https://github.com/libexpat/libexpat
https://github.com/libexpat/libexpat/issues/1160
https://github.com/libexpat/libexpat/pull/1433
https://www.vulncheck.com/advisories/libexpat-through-2.9.0-denial-of-service-via-billion-laughs-detection-delay

Configurations

No configuration.

History

22 Oct 2026, 20:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-22 20:17

Updated : 2026-10-23 21:17

NVD link : CVE-2026-115506

Mitre link : CVE-2026-115506

CVE.ORG link : CVE-2026-115506

JSON object : View

Products Affected

No product.

CWE

CWE-776

Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')

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