{"id":"CVE-2026-80205","state":"PUBLISHED","title":"NLTK before 3.10.0 ReDoS via Text.findall() unvalidated regex","description":"NLTK versions before 3.10.0 contain a regular expression denial of service vulnerability in Text.findall() and TokenSearcher.findall() methods that accept user-supplied regular expressions without validation or timeout. Attackers can supply crafted regex patterns that cause catastrophic backtracking, resulting in indefinite CPU saturation and denial of service to all users of the Python process.","publishedAt":"2026-08-26T10:28:14.352Z","updatedAt":"2026-09-01T22:06:44.235Z","severity":{"score":8.7,"label":"High","version":"4.0","vector":"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","source":"VulnCheck"},"assigner":"VulnCheck","products":["nltk nltk"],"affected":[{"vendor":"nltk","product":"nltk","packageURL":"pkg:pypi/nltk","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"3.10.0","versionType":"semver"},{"version":"3.10.0","status":"unaffected","versionType":"semver"}]}],"references":["https://github.com/nltk/nltk/security/advisories/GHSA-rrv8-h7p8-rx55","https://www.vulncheck.com/advisories/nltk-before-3.10.0-redos-via-text-findall-unvalidated-regex","http://www.openwall.com/lists/oss-security/2026/09/01/3"],"weaknesses":["CWE-1333"],"ingestedAt":"2026-10-29T20:13:07.220Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/80xxx/CVE-2026-80205.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-80205","state":"PUBLISHED","datePublished":"2026-08-26T10:28:14.352Z","dateUpdated":"2026-09-01T22:06:44.235Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-08-25T23:15:39.155Z"},"containers":{"cna":{"title":"NLTK before 3.10.0 ReDoS via Text.findall() unvalidated regex","descriptions":[{"lang":"en","value":"NLTK versions before 3.10.0 contain a regular expression denial of service vulnerability in Text.findall() and TokenSearcher.findall() methods that accept user-supplied regular expressions without validation or timeout. Attackers can supply crafted regex patterns that cause catastrophic backtracking, resulting in indefinite CPU saturation and denial of service to all users of the Python process."}],"affected":[{"vendor":"nltk","product":"nltk","packageURL":"pkg:pypi/nltk","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"3.10.0","versionType":"semver"},{"version":"3.10.0","status":"unaffected","versionType":"semver"}]}],"references":[{"url":"https://github.com/nltk/nltk/security/advisories/GHSA-rrv8-h7p8-rx55","tags":["vendor-advisory"],"name":"GitHub Security Advisory (GHSA-rrv8-h7p8-rx55)"},{"url":"https://www.vulncheck.com/advisories/nltk-before-3.10.0-redos-via-text-findall-unvalidated-regex","name":"VulnCheck Advisory: NLTK before 3.10.0 ReDoS via Text.findall() unvalidated regex","tags":["third-party-advisory"]}],"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"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-1333","lang":"en","description":"Inefficient Regular Expression Complexity","type":"CWE"}]}],"providerMetadata":{"shortName":"VulnCheck","orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateUpdated":"2026-08-26T10:28:14.352Z"},"datePublic":"2026-08-12T00:00:00.000Z","cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:nltk:nltk:*:*:*:*:*:*:*:*","versionEndExcluding":"3.10.0"}]}]}],"credits":[{"lang":"en","value":"infycore","type":"reporter"},{"lang":"en","value":"ekaf","type":"analyst"},{"lang":"en","value":"agent-kira","type":"finder"}],"x_generator":{"engine":"vulncheck-endgame"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-26T15:58:57.043941Z","id":"CVE-2026-80205","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-26T16:09:59.270Z"}},{"title":"CVE Program Container","references":[{"url":"http://www.openwall.com/lists/oss-security/2026/09/01/3"}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2026-09-01T22:06:44.235Z"}}]}}}