Multiple vulnerabilities exist in the Link Layer Discovery Protocol (LLDP) implementation for Cisco Small Business RV Series Routers. An unauthenticated, adjacent attacker could execute arbitrary code or cause an affected router to leak system memory or reload. A memory leak or device reload would cause a denial of service (DoS) condition on an affected device. For more information about these vulnerabilities, see the Details section of this advisory. Note: LLDP is a Layer 2 protocol. To exploit these vulnerabilities, an attacker must be in the same broadcast domain as the affected device (Layer 2 adjacent).
Use CWE-119, Cisco vendor hub and Rv132w Firmware product page to widen CVE-2021-1309 into its surrounding weakness, vendor, and product context.
Compare it with CVE-2018-0125, CVE-2018-0127 and CVE-2021-1308 for nearby disclosures in the same product family. Additional editorial context is available in The Weekly Cybersecurity Brief: January 30th, 2026.