{"id":"CVE-2026-49854","state":"PUBLISHED","title":"Tornado: Out-of-bounds memory access in C extension","description":"Tornado is a Python web framework and asynchronous networking library. Prior to 6.5.6, the optional native extension tornado.speedups implemented websocket_mask without validating that the mask argument is exactly four bytes, allowing the C function to read up to three bytes beyond the provided buffer when reached through Tornado XSRF token decoding with the native extension active. This issue is fixed in version 6.5.6.","publishedAt":"2026-07-14T20:43:03.977Z","updatedAt":"2026-07-15T13:26:39.749Z","severity":{"score":5.3,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["tornadoweb tornado"],"affected":[{"vendor":"tornadoweb","product":"tornado","versions":[{"version":"< 6.5.6","status":"affected"}]}],"references":["https://github.com/tornadoweb/tornado/security/advisories/GHSA-cx3h-4qpv-8hc9","https://github.com/tornadoweb/tornado/pull/3626","https://github.com/tornadoweb/tornado/commit/96dc88c2a05705287856b2cd6b4b4034f9a6aaac","https://github.com/tornadoweb/tornado/releases/tag/v6.5.6"],"weaknesses":["CWE-126"],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/49xxx/CVE-2026-49854.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-49854","state":"PUBLISHED","datePublished":"2026-07-14T20:43:03.977Z","dateUpdated":"2026-07-15T13:26:39.749Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-01T22:03:19.640Z"},"containers":{"cna":{"title":"Tornado: Out-of-bounds memory access in C extension","descriptions":[{"lang":"en","value":"Tornado is a Python web framework and asynchronous networking library. Prior to 6.5.6, the optional native extension tornado.speedups implemented websocket_mask without validating that the mask argument is exactly four bytes, allowing the C function to read up to three bytes beyond the provided buffer when reached through Tornado XSRF token decoding with the native extension active. This issue is fixed in version 6.5.6."}],"affected":[{"vendor":"tornadoweb","product":"tornado","versions":[{"version":"< 6.5.6","status":"affected"}]}],"references":[{"url":"https://github.com/tornadoweb/tornado/security/advisories/GHSA-cx3h-4qpv-8hc9","name":"https://github.com/tornadoweb/tornado/security/advisories/GHSA-cx3h-4qpv-8hc9","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/tornadoweb/tornado/pull/3626","name":"https://github.com/tornadoweb/tornado/pull/3626","tags":["x_refsource_MISC"]},{"url":"https://github.com/tornadoweb/tornado/commit/96dc88c2a05705287856b2cd6b4b4034f9a6aaac","name":"https://github.com/tornadoweb/tornado/commit/96dc88c2a05705287856b2cd6b4b4034f9a6aaac","tags":["x_refsource_MISC"]},{"url":"https://github.com/tornadoweb/tornado/releases/tag/v6.5.6","name":"https://github.com/tornadoweb/tornado/releases/tag/v6.5.6","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":5.3,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-126","lang":"en","description":"CWE-126: Buffer Over-read","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-07-14T20:43:03.977Z"},"source":{"advisory":"GHSA-cx3h-4qpv-8hc9","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-15T13:23:13.452445Z","id":"CVE-2026-49854","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":"2026-07-15T13:26:39.749Z"}}]}}}