Traefik is an HTTP reverse proxy and load balancer. In versions 2.11.27 and below, 3.0.0 through 3.4.4 and 3.5.0-rc1, a path traversal vulnerability was discovered in WASM Traefik’s plugin installation mechanism. By supplying a maliciously crafted ZIP archive containing file paths with ../ sequences, an attacker can overwrite arbitrary files on the system outside of the intended plugin directory. This can lead to remote code execution (RCE), privilege escalation, persistence, or denial of service. This is fixed in versions 2.11.28, 3.4.5 and 3.5.0.

Traefik is an HTTP reverse proxy and load balancer. For versions prior to 2.11.32 and 2.11.31 through 3.6.2, requests using PathPrefix, Path or PathRegex matchers can bypass path normalization. When Traefik uses path-based routing, requests containing URL-encoded restricted characters (/, \, Null, ;, ?, #) can bypass the middleware chain and reach unintended backends. For example, a request to http://mydomain.example.com/admin%2F could reach service-a without triggering my-security-middleware, bypassing security controls for the /admin/ path. This issue is fixed in versions 2.11.32 and 3.6.3.

Traefik is an HTTP reverse proxy and load balancer. Versions 3.5.0 through 3.6.2 have inverted TLS verification logic in the nginx.ingress.kubernetes.io/proxy-ssl-verify annotation. Setting the annotation to "on" (intending to enable backend TLS certificate verification) actually disables verification, allowing man-in-the-middle attacks against HTTPS backends when operators believe they are protected. This issue is fixed in version 3.6.3.