A cross-namespace authorization flaw in multicluster-observability-addon allows a user with permission to modify a managed cluster’s ManagedClusterAddOn configuration to reference ClusterLogForwarder or OpenTelemetryCollector resources outside the permitted namespace. If those resources reference Secrets, the add-on may copy the referenced Secrets to the attacker-controlled managed cluster.

Quarkus HTTP path-based authorization policies can be bypassed using encoded semicolons (%3B) to smuggle matrix parameters past the security layer, and using encoded slashes (%2F) or backslashes (%5C) to access protected static resources. This is a distinct issue from CVE-2026-39852, which addressed only literal semicolon stripping. ### Technical Details The security layer (AbstractPathM

fast-uri versions 2.3.1 through 3.1.2 and 4.0.0 fail to canonicalize Unicode (IDN) hostnames for HTTP-family URLs. The IDN conversion path calls a helper that does not exist on the global URL constructor, silently leaving the host in its original Unicode form while normalize() and equal() still return values that differ from a WHATWG-compatible URL parser. Applications that use fast-uri to enforce

Peplink InControl 2 through 2.14.2 before 2026-06-03 allows use of a semicolon to bypass access-control rules for certain /rest/o/{orgId} endpoints.