GO-2026-4981

    Dashboard / Vulnerabilities / GO-2026-4981

    GO-2026-4981

    Published: 7 May 2026Last Modified: 10 Sept 2026

    Summary: Crash when handling long CNAME response in net

    Details: When using LookupCNAME with the cgo DNS resolver, a very long CNAME response can trigger a double-free of C memory and a crash.

    References: https://go.dev/issue/78803, https://go.dev/cl/767860, https://groups.google.com/g/golang-announce/c/qcCIEXso47M

    Affected packages

    Package

    Name: stdlib

    Purl: pkg:golang/stdlib

    Affected ranges

    Type: SEMVER

    Events:

    Introduced- 0
    Fixed -1.25.10

    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