CVE-2026-88008 Traefik: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') and Incorrect Authorization

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...

CVE-2026-88007

Traefik versions 2.11.0 through 2.11.57 and 3.7.13 contain a backend connection reuse flaw in the HTTP/3 entrypoint. The ConnContext does not call service.AddTransportOnContext, causing kerberosRoundTripper to share a single backend transport across all frontend connections rather than using a de...

CVE-2026-88004 Traefik entrypoint header-name sanitization bypassed via request trailers

Traefik is an open source HTTP reverse proxy and load balancer. From 3.2.0 until 3.7.13, Traefik entrypoint defenses aliasHeadersStrategy, underscoreHeadersStrategy, and forwardedHeaders inspect req.Header but not req.Trailer, allowing an unauthenticated client to submit an aliasing or trusted...

EUVD-2026-75538

Traefik is an open source HTTP reverse proxy and load balancer. From 3.2.0 until 3.7.13, Traefik entrypoint defenses aliasHeadersStrategy, underscoreHeadersStrategy, and forwardedHeaders inspect req.Header but not req.Trailer, allowing an unauthenticated client to submit an aliasing or trusted...

CVE-2026-88004 Traefik entrypoint header-name sanitization bypassed via request trailers

Traefik is an open source HTTP reverse proxy and load balancer. From 3.2.0 until 3.7.13, Traefik entrypoint defenses aliasHeadersStrategy, underscoreHeadersStrategy, and forwardedHeaders inspect req.Header but not req.Trailer, allowing an unauthenticated client to submit an aliasing or trusted...

CVE-2026-88004

Traefik is an open source HTTP reverse proxy and load balancer. From 3.2.0 until 3.7.13, Traefik entrypoint defenses aliasHeadersStrategy, underscoreHeadersStrategy, and forwardedHeaders inspect req.Header but not req.Trailer, allowing an unauthenticated client to submit an aliasing or trusted...

CVE-2026-88004 Traefik entrypoint header-name sanitization bypassed via request trailers

Traefik is an open source HTTP reverse proxy and load balancer. From 3.2.0 until 3.7.13, Traefik entrypoint defenses aliasHeadersStrategy, underscoreHeadersStrategy, and forwardedHeaders inspect req.Header but not req.Trailer, allowing an unauthenticated client to submit an aliasing or trusted...

CVE-2026-88004

Traefik (open source HTTP reverse proxy and load balancer) versions 3.2.0 through 3.7.12 have a header sanitization bypass. The entrypoint defenses aliasHeadersStrategy , underscoreHeadersStrategy , and forwardedHeaders inspect only req.Header but not req.Trailer. An unauthenticated client can pl...

CVE-2026-88879

Traefik (HTTP reverse proxy and load balancer) is vulnerable to identity spoofing via dot-form header aliasing in versions v1.x, v2.x–v2.11.55, and v3.0.0–v3.7.11. Because Go canonicalizes header names on dashes only, a client can send a dot-form alias (e.g., X.Authenticated.User) alongside the c...

CVE-2026-88879 Traefik before v2.11.56 Identity Spoofing via Header Alias

Traefik is an HTTP reverse proxy and load balancer. In Traefik v1.x, v2.x through v2.11.55, and v3.0.0 through v3.7.11, header names are canonicalized only on dashes, so X-Auth-User, XAuthUser and X.Auth.User are treated as three distinct headers by Traefik, while backends that derive variable...

CVE-2026-88879 Traefik before v2.11.56 Identity Spoofing via Header Alias

Traefik is an HTTP reverse proxy and load balancer. In Traefik v1.x, v2.x through v2.11.55, and v3.0.0 through v3.7.11, header names are canonicalized only on dashes, so X-Auth-User, XAuthUser and X.Auth.User are treated as three distinct headers by Traefik, while backends that derive variable...

CVE-2026-88879

Traefik is an HTTP reverse proxy and load balancer. In Traefik v1.x, v2.x through v2.11.55, and v3.0.0 through v3.7.11, header names are canonicalized only on dashes, so X-Auth-User, XAuthUser and X.Auth.User are treated as three distinct headers by Traefik, while backends that derive variable...

CVE-2026-88877 Traefik v3.7.0 Authentication Bypass via from-to-www-redirect

Traefik is a HTTP reverse proxy and load balancer. In versions = v3.7.0 and = v3.7.11, the Kubernetes ingress-nginx provider mishandles Ingresses that carry both an authentication annotation and the nginx.ingress.kubernetes.io/from-to-www-redirect annotation. For such Ingresses the provider creat...

OSEC-2026-20 Cstruct indexing bugs can corrupt filtered output and reverse parsing results

Several functions in cstruct may use wrong data, leading to unexpected exceptions and return corrupted data. Impact - Cstruct.filtermap writes retained bytes at their original input positions, producing corrupted output when earlier bytes are dropped. - Cstruct.tail rev:true removes two bytes...

PT-2026-89459

Name of the Vulnerable Software and Affected Versions Traefik versions 2.11.26 through 2.11.56 Traefik versions 3.4.2 through 3.7.12 Description Traefik contains a request smuggling issue related to the handling of the HTTP/1.1 Upgrade mechanism. The software forwards client-supplied Connection...

PT-2026-89472

Name of the Vulnerable Software and Affected Versions Traefik versions 1.x Traefik versions prior to 2.11.56 Traefik versions 3.0.0 through 3.7.11 Description Traefik fails to properly handle request headers that act as aliases for other header names. While Go treats headers like...

PT-2026-89452

Name of the Vulnerable Software and Affected Versions Traefik versions 3.2.0 through 3.7.12 Description Traefik entrypoint defenses aliasHeadersStrategy, underscoreHeadersStrategy, and forwardedHeaders inspect req.Header but fail to inspect req.Trailer. This allows an unauthenticated client to...

CVE-2026-73276

A flaw was found in the Erlang/OTP inets httpd server. This vulnerability allows a remote attacker to perform HTTP Request Smuggling due to the server silently dropping HTTP headers that contain whitespace between the header field-name and the colon. When deployed behind a reverse proxy that...

CVE-2026-16037

Observable timing discrepancy vulnerability in PayTR Payment and Electronic Money Institution Inc. PayTR Virtual Pos iFrame API WHMCS Module allows Black Box Reverse Engineering. This issue affects PayTR Virtual Pos iFrame API WHMCS Module: from v9.0.0 before v9.0.3...

CVE-2026-16037

CVE-2026-16037 is an observable timing discrepancy in the PayTR Virtual Pos iFrame API (v9x) WHMCS Module (versions v9.0.0 through before v9.0.3) that allows a callback authentication bypass via timing attack , enabling black box reverse engineering . The CNA-assigned CVSS 3.1 score is 7.5 (HIGH)...