{"cve":"CVE-2026-18503","nvd":{"published":"2026-08-10T14:17:21.560","modified":"2026-10-23T20:10:00.160","status":"Awaiting Analysis","description":"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().","cvss_v4":{"vector":"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","score":2.4},"cvss_v3":null,"cwes":["CWE-1176"],"references":["https://github.com/python/cpython/commit/063d4555c94ef412c731527dbf30193327f2ee82","https://github.com/python/cpython/commit/476fb09cdb0d73e645849d98c610e7e5697ce7c9","https://github.com/python/cpython/commit/89f29c760c02774b099ddd6863268eb13fa3946a","https://github.com/python/cpython/commit/b09a67a20c464f8288c9f9a6b9c7082a74560024","https://github.com/python/cpython/commit/b30c7fa9edd921a118f286e9f90f560777fa693b"],"products":[],"source":"nvd","synced_at":"2026-10-24T16:53:34.184483516+00:00"},"epss":{"cve":"CVE-2026-18503","score":0.00119,"percentile":0.0177,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}