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    CVE-2026-18503

    Attacker-controlled CSV samples can trigger super-linear regular-expression work during dialect sniffing and consume significant CPU when applications pass unbounded input to csv.Sniffer.sniff().

    Published:Aug 10, 2026
    Last Modified:Aug 18, 2026
    EPS:Aug 10, 2026
    EPSS Score:0.00119
    CVSS Score:2.8

    Affected Products

    Vendor
    Python
    Product
    Cpython

    Exploits

    No exploit reference

    Common Attack Pattern Enumeration and Classification (CAPEC)

    CAPEC-492 Regular Expression Exponential Blowup

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    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High