GO-2026-6354

    Dashboard / Vulnerabilities / GO-2026-6354

    GO-2026-6354

    Published: 2 Sept 2026Last Modified: 3 Sept 2026

    Summary: Prevent DoS on deadlocked undecided channel in golang.org/x/crypto/ssh

    Details: Previously, a channel registered in the mux's chanList is not usable until it is established. A malicious peer was able flood the channel's incomingRequests, deadlocking the entire connection. Now, we add an atomic established state, set when a channel becomes usable. Until such a time, handlePacket drops every packet other than the open confirmation/failure, without blocking and without tearing down the connection.

    References: https://go.dev/issue/81316, https://go.dev/cl/826504, https://groups.google.com/g/golang-announce/c/1y3fb2np35U

    Affected packages

    Package

    Name: golang.org/x/crypto

    Purl: pkg:golang/golang.org/x/crypto

    Affected ranges

    Type: SEMVER

    Events:

    Introduced- 0
    Fixed -0.56.0

    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