libnv Header Validation Failure Enables Heap Buffer Overflow

CVE-2026-35547 is a heap buffer overflow vulnerability in libnv, a message processing library, caused by insufficient validation of incoming message headers. When libnv processes a message header without properly verifying the declared message size, an attacker can craft a malicious message that writes beyond allocated heap boundaries. This vulnerability affects any system or application relying on libnv for message handling, potentially impacting embedded systems, network services, and privileged processes. With a CVSS score of 8.1, the impact is significant: attackers can trigger denial of service through system crashes, corrupt memory to achieve arbitrary code execution, or exploit the vulnerability from an unprivileged context to escalate privileges to higher privilege levels.

While currently unmapped to specific MITRE ATT&CK techniques, Casky's 754 security skills powered by Claude AI with extended reasoning would detect the attack patterns underlying this vulnerability during behavioral analysis and memory inspection. A practitioner using Casky would identify suspicious patterns such as: (1) process crashes immediately following receipt of specially crafted network messages or inter-process communications, (2) heap corruption indicators in memory dumps, (3) unexpected privilege escalation attempts originating from unprivileged processes, and (4) anomalous message header fields with size declarations mismatched against actual payload lengths. By correlating these signals with the underlying CWE-122 (heap-based buffer overflow) and CWE-130 (improper validation of array index) weaknesses, Casky's AI reasoning engine would surface this as a likely exploitation attempt, enabling security teams to rapidly isolate affected systems and trace the attack origin before privilege escalation occurs.