GO-2026-6611

    Dashboard / Vulnerabilities / GO-2026-6611

    GO-2026-6611

    Published: 8 Oct 2026Last Modified: 8 Oct 2026

    Summary: Excessive CPU consumption from repeated initial window changes in net/http

    Details: A malicious HTTP/2 peer can cause excessive CPU consumption in the client or server by opening a large number of streams and then sending many small SETTINGS frames containing SETTINGS_INITIAL_WINDOW_SIZE values.

    References: https://go.dev/cl/847186, https://go.dev/cl/847308, https://go.dev/issue/81742, https://groups.google.com/g/golang-announce/c/U2fTuyDJznI, https://groups.google.com/g/golang-announce/c/ZPwCyRUuGBs

    Affected packages

    Package

    Name: stdlib

    Purl: pkg:golang/stdlib

    Affected ranges

    Type: SEMVER

    Events:

    Introduced- 0
    Fixed -1.26.9

    Affected versions

    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