Hi, The following vulnerability was published for dia. CVE-2026-77658[0]: | A stack-based buffer overflow vulnerability exists in the Dia | diagram editor when processing Network Bus objects from Dia XML | project files. In objects/network/bus.c, bus_load() reads the | number of bus handles from the file attribute "bus_handles" using | attribute_num_data() without validating an upper bound: | bus->num_handles = attribute_num_data(attr); When a bus handle is | subsequently moved, bus_handle_moved() allocates two temporary | arrays on the stack: parallel = (real *)g_alloca(num_handles * | sizeof(real)); perp = (real *)g_alloca(num_handles * | sizeof(real)); Because num_handles is fully attacker-controlled via | the project file, sufficiently large values (for example 262144 or | higher) cause g_alloca() to consume more stack space than the | default thread stack limit (typically 8 MB on Linux), resulting in | stack overflow, SIGSEGV, and potential stack frame / return-address | corruption. An attacker can embed a Bus object with an excessive | bus_handles count in a malicious .dia file. Exploitation requires | the victim to open the file in Dia (file dialog, command line, or | file association) and trigger handle manipulation (moving a bus | handle), which exercises the vulnerable code path. The identical | g_alloca pattern is present in objects/Misc/tree.c (copied from | bus.c) and is likely vulnerable to the same class of attack via Tree | objects. Affected versions: Dia 0.98.0 and earlier versions | containing this code; issue confirmed on upstream master as of | 2026-08-21. Upstream report: | https://gitlab.gnome.org/GNOME/dia/-/issues/581 https://gitlab.gnome.org/GNOME/dia/-/issues/581 If you fix the vulnerability please also make sure to include the CVE (Common Vulnerabilities & Exposures) id in your changelog entry. For further information see: [0] https://security-tracker.debian.org/tracker/CVE-2026-77658 https://www.cve.org/CVERecord?id=CVE-2026-77658 Please adjust the affected versions in the BTS as needed.