CWEweakness
CWE-758 Reliance on Undefined, Unspecified, or Implementation-Defined Behavior
- Abstraction
- Class
- Structure
- Simple
- Status
- Incomplete
- Languages
- Not Language-Specific
- CWE version
- 5.0
Description
The product uses an API function, data structure, or other entity in a way that relies on properties that are not always guaranteed to hold for that entity.
Common consequences
• Other: Reduce Maintainability, Unexpected State, Quality Degradation
Detection methods
• Fuzzing: Fuzz testing (fuzzing) is a powerful technique for generating large numbers of diverse inputs - either randomly or algorithmically - and dynamically invoking the code with those inputs. Even with random inputs, it is often capable of generating unexpected results such as crashes, memory corruption, or resource consumption. Fuzzing effectively produces repeatable test cases that clearly indicate bugs, which helps developers to diagnose the issues.
Observed examples
• CVE-2006-1902: Change in C compiler behavior causes resultant buffer overflows in programs that depend on behaviors that were undefined in the C standard.
Related
Observed example · CVE (1)
- CVE-2006-1902 fold_binary in fold-const.c in GNU Compiler Collection (gcc) 4.1 improperly handles pointer overflow when folding a certain expr comparison… vulnerability
Child of · CWE (1)
- CWE-710 Improper Adherence to Coding Standards weakness
Referenced by CVE · weakness (32)
- CVE-2026-119133 Wasmtime 47.0.0 before 48.0.6 and 49.0.0 before 49.0.3 contains a memory misalignment flaw in VMContext layout that causes undefined… vulnerability
- CVE-2026-100771 Undefined behavior in the DOM: Streams component. vulnerability
- CVE-2026-54604 OpenSlide is a C library for reading whole slide image files. vulnerability
- CVE-2026-16441 In Eclipse OpenJ9 versions up to 0.60, when executing class files where a previously concrete superclass method has been recompiled as… vulnerability
- CVE-2026-50185 RustCrypto CMOV provides conditional move CPU intrinsics which are guaranteed on major platforms to execute in constant-time and not be… vulnerability
- CVE-2024-58350 Ghidra before 11.2 contains a use after free vulnerability in the Sleigh backend caused by undefined static initialization order of the… vulnerability
- CVE-2026-31436 In the Linux kernel, the following vulnerability has been resolved: dmaengine: idxd: fix possible wrong descriptor completion in… vulnerability
- CVE-2026-40279 BACnet Stack is a BACnet open source protocol stack C library for embedded systems. vulnerability
- CVE-2026-34533 iccDEV provides a set of libraries and tools for working with ICC color management profiles. vulnerability
- CVE-2026-34537 iccDEV provides a set of libraries and tools for working with ICC color management profiles. vulnerability
- CVE-2026-34547 iccDEV provides a set of libraries and tools for working with ICC color management profiles. vulnerability
- CVE-2026-34549 iccDEV provides a set of libraries and tools for working with ICC color management profiles. vulnerability
- CVE-2026-28528 BlueKitchen BTstack versions prior to 1.8.1 contain an out-of-bounds read vulnerability in the AVRCP Browsing Target GET_FOLDER_ITEMS… vulnerability
- CVE-2026-4705 Undefined behavior in the WebRTC: Signaling component. vulnerability
- CVE-2026-4718 Undefined behavior in the WebRTC: Signaling component. vulnerability
- CVE-2026-4724 Undefined behavior in the Audio/Video component. vulnerability
- CVE-2026-23274 In the Linux kernel, the following vulnerability has been resolved: netfilter: xt_IDLETIMER: reject rev0 reuse of ALARM timer labels… vulnerability
- CVE-2026-24404 iccDEV provides libraries and tools for interacting with, manipulating, and applying ICC color management profiles. vulnerability
- CVE-2026-24407 iccDEV provides libraries and tools for interacting with, manipulating, and applying ICC color management profiles. vulnerability
- CVE-2026-24409 iccDEV provides libraries and tools for interacting with, manipulating, and applying ICC color management profiles. vulnerability
- CVE-2026-24410 iccDEV provides libraries and tools for interacting with, manipulating, and applying ICC color management profiles. vulnerability
- CVE-2026-24411 iccDEV provides libraries and tools for interacting with, manipulating, and applying ICC color management profiles. vulnerability
- CVE-2026-22858 FreeRDP is a free implementation of the Remote Desktop Protocol. vulnerability
- CVE-2026-21684 iccDEV provides a set of libraries and tools that allow for the interaction, manipulation, and application of International Color… vulnerability
- CVE-2026-21685 iccDEV provides a set of libraries and tools that allow for the interaction, manipulation, and application of International Color… vulnerability
- CVE-2026-21686 iccDEV provides a set of libraries and tools that allow for the interaction, manipulation, and application of International Color… vulnerability
- CVE-2026-21687 iccDEV provides a set of libraries and tools that allow for the interaction, manipulation, and application of International Color… vulnerability
- CVE-2026-21677 iccDEV provides a set of libraries and tools for working with ICC color management profiles. vulnerability
- CVE-2025-54811 OpenPLC_V3 has a vulnerability in the enipThread function that occurs due to the lack of a return value. vulnerability
- CVE-2025-55160 ImageMagick is free and open-source software used for editing and manipulating digital images. vulnerability
Referenced by CWE · child of (8)
- CWE-1038 Insecure Automated Optimizations weakness
- CWE-1102 Reliance on Machine-Dependent Data Representation weakness
- CWE-1103 Use of Platform-Dependent Third Party Components weakness
- CWE-1105 Insufficient Encapsulation of Machine-Dependent Functionality weakness
- CWE-474 Use of Function with Inconsistent Implementations weakness
- CWE-562 Return of Stack Variable Address weakness
- CWE-587 Assignment of a Fixed Address to a Pointer weakness
- CWE-588 Attempt to Access Child of a Non-structure Pointer weakness