{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-126298","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","state":"PUBLISHED","assignerShortName":"VulnCheck","dateReserved":"2026-11-10T20:15:54.612Z","datePublished":"2026-11-13T09:36:27.213Z","dateUpdated":"2026-11-13T22:30:00.165Z"},"containers":{"cna":{"providerMetadata":{"orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","shortName":"VulnCheck","dateUpdated":"2026-11-13T09:36:27.213Z"},"datePublic":"2026-10-26T00:00:00.000Z","title":"NLTK before 3.10.4 Quadratic CPU Denial of Service via Tree.chomsky_normal_form","descriptions":[{"lang":"en","value":"NLTK before 3.10.4 contains a denial of service vulnerability in Tree.chomsky_normal_form that allows remote attackers to exhaust CPU through quadratic-time right-factor binarization using list.pop(0). Attackers can supply a wide flat treebank tree parsed by Tree.fromstring to force tens of seconds of single-threaded CPU consumption, blocking the processing thread."}],"problemTypes":[{"descriptions":[{"lang":"en","description":"Uncontrolled Resource Consumption","cweId":"CWE-400","type":"CWE"}]}],"affected":[{"vendor":"nltk","product":"nltk","defaultStatus":"unaffected","packageURL":"pkg:pypi/nltk","versions":[{"version":"0","status":"affected","versionType":"semver","lessThan":"3.10.4"},{"version":"3.10.4","status":"unaffected","versionType":"semver"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:nltk:nltk:*:*:*:*:*:*:*:*","versionEndExcluding":"3.10.4"}]}]}],"metrics":[{"format":"CVSS","cvssV4_0":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":8.7,"baseSeverity":"HIGH"}},{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH","baseScore":7.5,"baseSeverity":"HIGH"}}],"references":[{"url":"https://github.com/nltk/nltk/security/advisories/GHSA-r53h-rw34-8h97","tags":["vendor-advisory"],"name":"GitHub Security Advisory (GHSA-r53h-rw34-8h97)"},{"name":"VulnCheck Advisory: NLTK before 3.10.4 Quadratic CPU Denial of Service via Tree.chomsky_normal_form","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/nltk-before-3.10.4-quadratic-cpu-denial-of-service-via-tree-chomsky-normal-form"}],"credits":[{"lang":"en","value":"manus-pi","type":"reporter"},{"lang":"en","value":"manus-use","type":"reporter"}],"x_generator":{"engine":"vulncheck-endgame"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-11-13T16:34:33.596773Z","id":"CVE-2026-126298","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-11-13T22:30:00.165Z"}}]}}