{"id":"CVE-2026-115506","title":"libexpat through 2.9.0 Denial of Service via Billion Laughs Detection Delay","summary":"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 wi…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cvssSource":"cna","cwe":["CWE-776"],"vendor":"libexpat","product":"libexpat","affected":["libexpat <= 2.9.0"],"ssvc":{"exploitation":"poc","automatable":"yes","technicalImpact":"partial","timestamp":"2026-10-23T18:03:08.684378Z"},"exploitAvailable":true,"published":"2026-10-22","updated":"2026-10-23","sourceUpdated":"2026-10-23T21:06:43.010Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-115506","references":[{"url":"https://github.com/libexpat/libexpat/pull/1433"},{"url":"https://github.com/libexpat/libexpat/issues/1160"},{"url":"https://github.com/hannob/lololol"},{"url":"https://github.com/libexpat/libexpat"},{"url":"https://www.vulncheck.com/advisories/libexpat-through-2.9.0-denial-of-service-via-billion-laughs-detection-delay","label":"VulnCheck Advisory: libexpat through 2.9.0 Denial of Service via Billion Laughs Detection Delay"}],"tags":["cve.org","exploit-available"],"epss":0.00455,"epssPercentile":0.39329,"ingestedAt":"2026-10-22T22:00:50.411Z","slug":"CVE-2026-115506","body":"## Overview\n\nlibexpat 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.\n\n## Affected\n\n- `libexpat <= 2.9.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":53,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[{"seq":228388,"id":"CVE-2026-115506","ts":1792791576222,"field":"exploit_available","old":"false","new":"true"}]}