PatchSiren cyber security CVE debrief

CVE-2026-46529 mate-desktop CVE debrief

CVE-2026-46529 is a high-severity remote code execution vulnerability in Atril Document Viewer, a default document reader for the MATE desktop environment. The vulnerability, rated 8.4 CVSS, allows an attacker to execute arbitrary code as the user by tricking them into clicking a link inside a malicious PDF document. The PDF can be packaged as a polyglot file that is simultaneously a valid PDF and a valid ELF shared library, making the attack a single-file, single-click, configuration-independent RCE on stock atril installations. The root cause is `shell/ev-application.c:ev_spawn`, which builds a command line from attacker-controlled PDF link-destination fields without applying `g_shell_quote`. The cmdline is then handed to `g_app_info_create_from_commandline`, which shell-parses it back into argv — splitting any embedded `--gtk-module=PATH` into a separate argv element. GTK then `dlopen()`s the path during init, running any `__attribute__((constructor))` it finds. Versions 1.26.3 and 1.28.4 contain a patch for the issue.