CVE-2026-115506
highlibexpat through 2.9.0 contains a denial of service vulnerability because billion laughs protection in accountingDiffTolerated() in xmlparse.c detects entity a…
Vendor / product: Libexpat Project — libexpat
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
7.5
7.5 (CVSS v3.1)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Severity source: NVD CVSS v3.1 (disclosure@vulncheck.com)
Timeline (UTC)
Published: 2026-10-22 20:17
Modified: 2026-11-02 18:27
NVD status: Analyzed
Last synced 1 day ago
Verified against the source API 2026-11-03 07:34 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).
Affected products
libexpat_project / libexpat ≤2.9.0
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
Vendor advisory: https://github.com/libexpat/libexpat/issues/1160
Patch / mitigation: https://github.com/hannob/lololol
Patch / mitigation: https://github.com/libexpat/libexpat/pull/1433
References
- https://github.com/hannob/lololol disclosure@vulncheck.com
- https://github.com/libexpat/libexpat disclosure@vulncheck.com
- https://github.com/libexpat/libexpat/issues/1160 disclosure@vulncheck.com
- https://github.com/libexpat/libexpat/pull/1433 disclosure@vulncheck.com
- https://www.vulncheck.com/advisories/libexpat-through-2.9.0-denial-of-service-via-billion-... disclosure@vulncheck.com
Data sources
NVD CVE API 2.0 — fetched 2026-11-03 07:34 UTC · record ↗