{"id":"CVE-2026-35536","aliases":["GHSA-78cv-mqj4-43f7","GHSA-fqwm-6jpj-5wxc","PYSEC-2026-2287"],"url":"https://o3.security/vulnerability/CVE-2026-35536","summary":"Tornado has incomplete validation of cookie attributes","details":"Values passed to the `domain`, `path`, and `samesite` arguments of `RequestHandler.set_cookie` were not completely validated in versions of Tornado prior to 6.5.5. In particular, semicolons would be allowed, which could be used to inject attacker-controlled values for other cookie attributes.","published":"2026-04-03T02:25:57.427Z","modified":"2026-08-12T03:51:25.472256517Z","cvss":{"score":7.2,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"tornado","fixedVersion":"6.5.5"}],"fix":{"url":"https://github.com/tornadoweb/tornado/commit/24a2d96ea115f663b223887deb0060f13974c104","label":"tornadoweb/tornado@24a2d96"},"references":[{"type":"WEB","url":"https://github.com/tornadoweb/tornado/releases/tag/v6.5.5"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/35xxx/CVE-2026-35536.json"},{"type":"ADVISORY","url":"https://github.com/tornadoweb/tornado/security/advisories/GHSA-78cv-mqj4-43f7"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-35536"},{"type":"WEB","url":"https://github.com/tornadoweb/tornado/commit/24a2d96ea115f663b223887deb0060f13974c104"},{"type":"PACKAGE","url":"https://github.com/tornadoweb/tornado"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:25.472256517Z"}}