{"id":"CVE-2026-4224","state":"PUBLISHED","title":"Stack overflow parsing XML with deeply nested DTD content models","description":"When an Expat parser with a registered ElementDeclHandler parses an inline\ndocument type definition containing a deeply nested content model a C stack\noverflow occurs.","publishedAt":"2026-03-16T17:52:26.639Z","updatedAt":"2026-08-13T00:27:37.326Z","severity":{"score":6,"label":"Medium","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","source":"PSF"},"assigner":"PSF","products":["Python Software Foundation CPython"],"affected":[{"vendor":"Python Software Foundation","product":"CPython","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"3.10.21","versionType":"python"},{"version":"3.11.0","status":"affected","lessThan":"3.11.16","versionType":"python"},{"version":"3.12.0","status":"affected","lessThan":"3.12.14","versionType":"python"},{"version":"3.13.0","status":"affected","lessThan":"3.13.13","versionType":"python"},{"version":"3.14.0","status":"affected","lessThan":"3.14.4","versionType":"python"},{"version":"3.15.0a1","status":"affected","lessThan":"3.15.0a8","versionType":"python"}],"repo":"https://github.com/python/cpython"}],"references":["https://github.com/python/cpython/commit/eb0e8be3a7e11b87d198a2c3af1ed0eccf532768","https://mail.python.org/archives/list/security-announce@python.org/thread/5M7CGUW3XBRY7II4DK43KF7NQQ3TPZ6R/","https://github.com/python/cpython/issues/145986","https://github.com/python/cpython/pull/145987","https://github.com/python/cpython/commit/196edfb06a7458377d4d0f4b3cd41724c1f3bd4a","https://github.com/python/cpython/commit/e0a8a6da90597a924b300debe045cdb4628ee1f3","https://github.com/python/cpython/commit/642865ddf4b232da1f3b1f7abcfa3254c4bfe785","https://github.com/python/cpython/commit/af856a7177326ac25d9f66cc6dd28b554d914fee","https://github.com/python/cpython/commit/24ce88b285f56ee11626cf5e472af3cd8cc7c621","http://www.openwall.com/lists/oss-security/2026/03/16/4"],"weaknesses":["CWE-674"],"ingestedAt":"2026-10-29T20:12:16.098Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/4xxx/CVE-2026-4224.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-4224","state":"PUBLISHED","datePublished":"2026-03-16T17:52:26.639Z","dateUpdated":"2026-08-13T00:27:37.326Z","assignerShortName":"PSF","assignerOrgId":"28c92f92-d60d-412d-b760-e73465c3df22","dateReserved":"2026-03-15T18:10:54.886Z"},"containers":{"cna":{"title":"Stack overflow parsing XML with deeply nested DTD content models","descriptions":[{"lang":"en","value":"When an Expat parser with a registered ElementDeclHandler parses an inline\ndocument type definition containing a deeply nested content model a C stack\noverflow occurs."}],"affected":[{"vendor":"Python Software Foundation","product":"CPython","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"3.10.21","versionType":"python"},{"version":"3.11.0","status":"affected","lessThan":"3.11.16","versionType":"python"},{"version":"3.12.0","status":"affected","lessThan":"3.12.14","versionType":"python"},{"version":"3.13.0","status":"affected","lessThan":"3.13.13","versionType":"python"},{"version":"3.14.0","status":"affected","lessThan":"3.14.4","versionType":"python"},{"version":"3.15.0a1","status":"affected","lessThan":"3.15.0a8","versionType":"python"}],"repo":"https://github.com/python/cpython"}],"references":[{"url":"https://github.com/python/cpython/commit/eb0e8be3a7e11b87d198a2c3af1ed0eccf532768","tags":["patch"]},{"url":"https://mail.python.org/archives/list/security-announce@python.org/thread/5M7CGUW3XBRY7II4DK43KF7NQQ3TPZ6R/","tags":["vendor-advisory"]},{"url":"https://github.com/python/cpython/issues/145986","tags":["issue-tracking"]},{"url":"https://github.com/python/cpython/pull/145987","tags":["patch"]},{"url":"https://github.com/python/cpython/commit/196edfb06a7458377d4d0f4b3cd41724c1f3bd4a","tags":["patch"]},{"url":"https://github.com/python/cpython/commit/e0a8a6da90597a924b300debe045cdb4628ee1f3","tags":["patch"]},{"url":"https://github.com/python/cpython/commit/642865ddf4b232da1f3b1f7abcfa3254c4bfe785","tags":["patch"]},{"url":"https://github.com/python/cpython/commit/af856a7177326ac25d9f66cc6dd28b554d914fee","tags":["patch"]},{"url":"https://github.com/python/cpython/commit/24ce88b285f56ee11626cf5e472af3cd8cc7c621","tags":["patch"]}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"PRESENT","attackVector":"NETWORK","baseScore":6,"baseSeverity":"MEDIUM","exploitMaturity":"NOT_DEFINED","privilegesRequired":"LOW","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"NONE","valueDensity":"NOT_DEFINED","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","version":"4.0","vulnAvailabilityImpact":"HIGH","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"providerMetadata":{"shortName":"PSF","orgId":"28c92f92-d60d-412d-b760-e73465c3df22","dateUpdated":"2026-08-13T00:27:37.326Z"},"credits":[{"lang":"en","type":"reporter","value":"Gil Portnoy"},{"lang":"en","type":"remediation developer","value":"Stan Ulbrych"},{"lang":"en","type":"remediation reviewer","value":"Bénédikt Tran"},{"lang":"en","type":"coordinator","value":"Stan Ulbrych"}],"source":{"discovery":"UNKNOWN"},"x_generator":{"engine":"Vulnogram 0.6.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-03-16T18:20:48.548008Z","id":"CVE-2026-4224","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-674","type":"CWE","lang":"en","description":"CWE-674 Uncontrolled Recursion"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-03-16T18:21:11.567Z"}},{"title":"CVE Program Container","references":[{"url":"http://www.openwall.com/lists/oss-security/2026/03/16/4"}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2026-03-16T23:08:21.692Z"}}]}}}