CVE-2025-34468
Severity CVSS v4.0:
HIGH
Type:
CWE-121
Stack-based Buffer Overflow
Publication date:
31/12/2025
Last modified:
31/12/2025
Description
libcoap versions up to and including 4.3.5, prior to commit 30db3ea, contain a stack-based buffer overflow in address resolution when attacker-controlled hostname data is copied into a fixed 256-byte stack buffer without proper bounds checking. A remote attacker can trigger a crash and potentially achieve remote code execution depending on compiler options and runtime memory protections. Exploitation requires the proxy logic to be enabled (i.e., the proxy request handling code path in an application using libcoap).
Impact
Base Score 4.0
8.20
Severity 4.0
HIGH