CVE-2026-88008

    Dashboard / Vulnerabilities / CVE-2026-88008

    CVE-2026-88008

    Published: 10 Sept 2026Last Modified: 11 Sept 2026

    Summary: Traefik: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') and Incorrect Authorization

    Details: Traefik is an open source HTTP reverse proxy and load balancer. From 2.11.26 until 2.11.57 and 3.7.13, Traefik forwards a client-supplied Connection header requesting Upgrade, the Upgrade: h2c token, and HTTP2-Settings to a shared backend. If the backend accepts h2c and returns 101 Switching Protocols, Traefik enters a raw tunnel and no longer applies routers, BasicAuth, ForwardAuth, IPAllowList, RateLimit, access logging, metrics, or tracing to later HTTP/2 requests, allowing an unauthenticated request through an unprotected route to reach protected paths on the same backend. This issue is fixed in 2.11.57 and 3.7.13.

    Affected packages

    Package

    Name:

    Purl:

    Affected ranges

    Type: GIT

    Events:

    Introduced- 8ae0379171cd04b60d7a1cb7da124ef56e8fc9f1

    Affected versions

    v2.11.56
    v2.11.55
    v2.11.54
    v2.11.53
    v2.11.52
    v2.11.51
    v2.11.50
    v2.11.49
    v2.11.48
    v2.11.47
    v2.11.46
    v2.11.45
    v2.11.44
    v2.11.43
    v2.11.42
    v2.11.41
    v2.11.40
    v2.11.39
    v2.11.38
    v2.11.37
    v2.11.36
    v2.11.35
    v2.11.34
    v2.11.33
    v2.11.32
    v2.11.31
    v2.11.30
    v2.11.29
    v2.11.28
    v2.11.27
    v2.11.26

    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