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    CVE-2026-40209

    An attacker might be able to cause outgoing TCP connections to backend to be stuck until a timeout occurs instead of being released immediately, by sending IXFR queries. This could be used to cause a denial of service if there is a limit to the number of concurrent connections to this backend, or if the process runs out of file descriptors.

    Published:Jun 25, 2026
    Last Modified:Jun 25, 2026
    EPS:Jun 25, 2026
    EPSS Score:
    CVSS Score:5.3

    Affected Products

    Vendor
    Powerdns
    Product
    Dnsdist

    Exploits

    No exploit reference

    Common Attack Pattern Enumeration and Classification (CAPEC)

    CAPEC-469 HTTP DoS

    Related CVEs

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    CVE-2026-40210 (CVSS 4.8) — An out-of-bounds read might happen when SetMacAddrAction is used, potentially resulting in uninitialized memor…
    CVE-2026-40208 (CVSS 3.7) — An attacker might be able to delay the processing of DoH3 queries by sending DoH3 GET queries with an invalid …
    CVE-2026-40011 (CVSS 3.7) — An attacker sending a large number of crafted DNS queries might be able to trigger a dynamic block being inser…
    CVE-2026-33593 (CVSS 7.5) — A client can trigger a divide by zero error leading to crash by sending a crafted DNSCrypt query.…
    CVE-2026-33594 (CVSS 5.3) — A client can trigger excessive memory allocation by generating a lot of queries that are routed to an overload…
    CVE-2026-33595 (CVSS 5.3) — A client can trigger excessive memory allocation by generating a lot of errors responses over a single DoQ and…
    CVE-2026-33597 (CVSS 3.7) — PRSD detection denial of service…
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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