CVE-2026-115506

EUVD-2026-108338
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.
XML Entity Expansion
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
VulnCheckCNA
7.5 HIGH
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: 27.48%
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
libexpat_projectlibexpat
𝑥
≤ 2.9.0
CNA
Debian logo
Debian Releases
Debian Product
Codename
expat
bookworm
vulnerable
bookworm (security)
vulnerable
forky
vulnerable
sid
vulnerable
trixie
vulnerable
trixie (security)
vulnerable
Common Weakness Enumeration
Vulnerability Media Exposure
References
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