CVE-2026-5674 is a CVSS 8.8 sandbox escape in PipeWire's PulseAudio compatibility layer. Three chained flaws enable the exploit: the authentication cookie is read but never verified, module loading is enabled by default for 'authenticated' clients, and module-ladspa-sink calls dlopen() on arbitrary paths without validation. A Flatpak app with only --socket=pulseaudio permission can write a malicious shared library to /tmp, send a junk cookie, load the module pointing at that library, and achieve arbitrary code execution as the logged-in user — no elevated privileges or race conditions required. Discovered by Johann Rehberger using an AI-assisted research pipeline (Claude Code/Opus), the bug was confirmed on PipeWire 1.0.5, reported to Red Hat on April 5, and patched by restricting dlopen() from loading libraries off arbitrary absolute paths. Red Hat shipped RHSA-2026:47083 on July 28. Defenders should patch PipeWire, audit Flatpak apps requesting --socket=pulseaudio with filesystem access, and strip unnecessary permissions.
