ESF-IDF: Out-of-bounds Read in lwIP DHCP Server Option Parser
CVE-2026-45160
What is CVE-2026-45160?
ESF-IDF is the Espressif Internet of Things (IOT) Development Framework. In versions 5.2.7, 5.3.5, 5.4.4, 5.5.4, and 6.0.1, an out-of-bounds read flaw exists in the DHCP server option parser (parse_options() in components/lwip/apps/dhcpserver/dhcpserver.c) shipped with ESP-IDF's lwIP component. The parser walks the BOOTP/DHCP options field without validating that each option's length byte and declared payload length stay within the received packet buffer. A crafted DHCP request can cause the parser to read past the end of the options buffer into adjacent heap memory. The issue affects the DHCP server used by ESP-IDF's SoftAP and any configuration where the device runs as a DHCP server on a local network. This issue has been patched in versions 5.2.8, 5.3.6, 5.4.5, 5.5.5, and 6.0.2.
Affected Version(s)
esp-idf = 5.2.7 = 5.2.7
esp-idf = 5.3.5 = 5.3.5
esp-idf = 5.4.4 = 5.4.4