{"resultsPerPage":1,"startIndex":0,"totalResults":1,"format":"NVD_CVE","version":"2.0","timestamp":"2026-04-20T23:44:40.263","vulnerabilities":[{"cve":{"id":"CVE-2025-67726","sourceIdentifier":"security-advisories@github.com","published":"2025-12-12T07:15:44.920","lastModified":"2025-12-22T18:56:47.850","vulnStatus":"Analyzed","cveTags":[],"descriptions":[{"lang":"en","value":"Tornado is a Python web framework and asynchronous networking library. Versions 6.5.2 and below use an inefficient algorithm when parsing parameters for HTTP header values, potentially causing a DoS. The _parseparam function in httputil.py is used to parse specific HTTP header values, such as those in multipart/form-data and repeatedly calls string.count() within a nested loop while processing quoted semicolons. If an attacker sends a request with a large number of maliciously crafted parameters in a Content-Disposition header, the server's CPU usage increases quadratically (O(n²)) during parsing. Due to Tornado's single event loop architecture, a single malicious request can cause the entire server to become unresponsive for an extended period. This issue is fixed in version 6.5.3."}],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":3.9,"impactScore":3.6}]},"weaknesses":[{"source":"security-advisories@github.com","type":"Primary","description":[{"lang":"en","value":"CWE-400"},{"lang":"en","value":"CWE-834"}]}],"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:tornadoweb:tornado:*:*:*:*:*:*:*:*","versionEndExcluding":"6.5.3","matchCriteriaId":"64279E50-159B-4CAB-9BD0-E2B764C3C40C"}]}]}],"references":[{"url":"https://github.com/tornadoweb/tornado/commit/771472cfdaeebc0d89a9cc46e249f8891a6b29cd","source":"security-advisories@github.com","tags":["Patch"]},{"url":"https://github.com/tornadoweb/tornado/releases/tag/v6.5.3","source":"security-advisories@github.com","tags":["Release Notes"]},{"url":"https://github.com/tornadoweb/tornado/security/advisories/GHSA-jhmp-mqwm-3gq8","source":"security-advisories@github.com","tags":["Vendor Advisory"]}]}}]}