Skipper is an HTTP router and reverse proxy for service composition. Prior to 0.27.35, the opaAuthorizeRequestWithBody filter in filters/openpolicyagent/openpolicyagent.go can allow an oversized declared Content-Length request to bypass a deny-on-presence Rego policy because ExtractHttpBodyOptionally leaves OPA with an empty parsedbody while forwarding the complete request body upstream. This incomplete remediation of CVE-2026-50197 affects deployments that authorize request-body content and exceed -open-policy-agent-max-request-body-size, which defaults to 1 MB. Policy logic that does not reject input.attributes.request.http.truncatedbody can therefore fail open and permit a forbidden payload to reach the protected service, while small bodies and the previously fixed chunked-body case are evaluated normally. This issue is fixed in version 0.27.35.
Skipper contains an incomplete fix for CVE-2026-50197 in which oversized request bodies bypass Open Policy Agent (OPA) deny-on-presence Rego policies. When a request body exceeds the configured maxBodyBytes limit, Skipper forwards the full payload to the upstream service while OPA evaluates against an empty parsedbody, so policies that deny requests based on body content are not enforced and forbidden actions proceed. No fixed version is available; v0.27.26 adds documentation guidance only.
Impact
When running Skipper as an Ingress controller, users with permissions to create an Ingress and a Service of type ExternalName can create routes that enable them to use Skipper's network access to reach internal services.
Patches
https://github.com/zalando/skipper/releases/tag/v0.24.0 disables Kubernetes ExternalName by default.
Workarounds
Developers can allow list targets of an ExternalName by using -kubernetes-only-allowed-external-names=true and allow list via regular expressions -kubernetes-allowed-external-name '^[a-z][a-z0-9-.]+[.].allowed.example$'
References
https://kubernetes.io/docs/concepts/services-networking/service/#externalname
Impact
Arbitrary code execution through lua filters.
The default skipper configuration before v0.23 was -lua-sources=inline,file. The problem starts if untrusted users can create lua filters, because of -lua-sources=inline , for example through a Kubernetes Ingress resource. The configuration inline allows these user to create a script that is able to read the filesystem accessible to the skipper process and if the user has access to read the logs they an read skipper secrets.
Kubernetes example (vulnerability is not limited to Kubernetes) lua function request(ctx, params) local file = io.open('/var/run/secrets/kubernetes.io/serviceaccount/token', 'r') if file then local token = file:read('all') file:close() error('[EXFIL] ' .. token) -- Exfiltrate via error logs end end
Patches
https://github.com/zalando/skipper/releases/tag/v0.23.0 disables Lua by default.
Workarounds
You can reduce support of how you can pass lua filter script data by providing config for lua sources https://opensource.zalando.com/skipper/reference/scripts/#enable-and-disable-lua-sources. For example -lua-sources=file will only be exploitable if the attacker can create a lua script file on the target system.
References
https://opensource.zalando.com/skipper/reference/scripts/#enable-and-disable-lua-sources