CVE-2026-77658

Name of the Vulnerable Software and Affected Versions Dia versions prior to 0.98.1

Description A stack-based buffer overflow occurs when processing Network Bus objects from XML project files. The bus load() function reads the bus handles attribute using attribute num data() without validating an upper bound. When a bus handle is moved, the bus handle moved() function uses g alloca() to allocate two temporary arrays on the stack based on the num handles variable. An attacker can provide an excessively large value for num handles in a malicious .dia file, causing the application to exceed the thread stack limit, leading to a SIGSEGV (segmentation fault) and potential corruption of the stack frame or return address. This same pattern is also present in objects/Misc/tree.c and may affect Tree objects. Exploitation occurs when a user opens a malicious file and manipulates a bus handle.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.