CVE-2026-18503

{"id": "CVE-2026-18503", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-18503", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-08-10T17:56:17.853221Z"}}], "cvssMetricV40": [{"type": "Secondary", "source": "cna@python.org", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 2.4, "Automatable": "NOT_DEFINED", "attackVector": "LOCAL", "baseSeverity": "LOW", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "PASSIVE", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "LOW", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "NONE", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "LOW", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "affected": [{"source": "cna@python.org", "affectedData": [{"repo": "https://github.com/python/cpython", "vendor": "Python Software Foundation", "modules": ["csv"], "product": "CPython", "versions": [{"status": "affected", "version": "0", "lessThan": "3.10.21", "versionType": "python"}, {"status": "affected", "version": "3.11.0", "lessThan": "3.11.16", "versionType": "python"}, {"status": "affected", "version": "3.12.0", "lessThan": "3.12.14", "versionType": "python"}, {"status": "affected", "version": "3.13.0", "lessThan": "3.13.15", "versionType": "python"}, {"status": "affected", "version": "3.14.0", "lessThan": "3.14.7", "versionType": "python"}, {"status": "affected", "version": "3.15.0a1", "lessThan": "3.15.0rc1", "versionType": "python"}, {"status": "affected", "version": "3.16.0a1", "lessThan": "3.16.0", "versionType": "python"}], "defaultStatus": "unaffected"}]}], "published": "2026-08-10T14:17:21.560", "references": [{"url": "https://github.com/python/cpython/commit/063d4555c94ef412c731527dbf30193327f2ee82", "source": "cna@python.org"}, {"url": "https://github.com/python/cpython/commit/476fb09cdb0d73e645849d98c610e7e5697ce7c9", "source": "cna@python.org"}, {"url": "https://github.com/python/cpython/commit/89f29c760c02774b099ddd6863268eb13fa3946a", "source": "cna@python.org"}, {"url": "https://github.com/python/cpython/commit/b09a67a20c464f8288c9f9a6b9c7082a74560024", "source": "cna@python.org"}, {"url": "https://github.com/python/cpython/commit/b30c7fa9edd921a118f286e9f90f560777fa693b", "source": "cna@python.org"}, {"url": "https://github.com/python/cpython/commit/fd78b565d7c326f96ae903ab945b47f35d829cf4", "source": "cna@python.org"}, {"url": "https://github.com/python/cpython/issues/98820", "source": "cna@python.org"}, {"url": "https://github.com/python/cpython/pull/153694", "source": "cna@python.org"}, {"url": "https://mail.python.org/archives/list/security-announce@python.org/thread/KQ7NBMCPAZJHRROQXJQE4GMXGLD5KHBS/", "source": "cna@python.org"}], "vulnStatus": "Awaiting Analysis", "weaknesses": [{"type": "Secondary", "source": "cna@python.org", "description": [{"lang": "en", "value": "CWE-1176"}]}], "descriptions": [{"lang": "en", "value": "Attacker-controlled CSV samples can trigger super-linear \nregular-expression work during dialect sniffing and consume significant \nCPU when applications pass unbounded input to csv.Sniffer.sniff()."}, {"lang": "es", "value": "Muestras CSV controladas por el atacante pueden desencadenar un procesamiento de expresiones regulares superlineal durante la detecci\u00f3n de dialectos y consumir una cantidad significativa de CPU cuando las aplicaciones pasan una entrada ilimitada a csv.Sniffer.sniff()."}], "lastModified": "2026-10-23T20:10:00.160", "sourceIdentifier": "cna@python.org"}