Xdg Dbus Proxy CVE-2026-34080

xdg-dbus-proxy is a D-Bus message filtering proxy commonly used in Flatpak sandboxes to enforce security policies on inter-process communication. The vulnerability exists in the policy parsing logic, which is responsible for evaluating D-Bus access control rules before allowing message relay. The root cause is improper input validation and normalization of policy directives (CWE-1289: Improper Validation of Specified Quantity in Input). The parser checks for the exact string eavesdrop=true but does not account for whitespace variations or case sensitivity edge cases in policy rule evaluation. D-Bus messages intended to be restricted from eavesdropping become accessible when malformed policy rules pass the access control checks due to this parsing flaw.