CVE-2026-121288 · Infrastructure
NO FIX YET
A flaw lets an attacker on an adjacent network segment bypass RIPv2 MD5 authentication and have forged route updates accepted by the device. Injected routes can redirect traffic through attacker-controlled paths, create routing loops, or blackhole traffic.
first public Nov 10, 2026 · 2 sources
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Only devices that run RIPv2 with MD5 authentication configured on an interface are exposed, because the flaw requires that setting. An attacker must sit on an adjacent network segment that can send RIPv2 packets to the device. Networks that do not use RIP, or that use no RIPv2 MD5 authentication, can skip this.
Not affected if no-md5-auth, no-rip, not-adjacent-segment
Who cares network-gear, ripv2, routers
Unknown from the sources.
An unauthenticated attacker on an adjacent network segment can bypass MD5 authentication and have unauthorized RIP route updates accepted by the device. Successful exploitation requires that RIPv2 MD5 authentication is configured on the affected interface. An attacker who can inject crafted RIPv2 packets could cause the device to install routes that redirect network traffic through attacker-controlled paths, create routing loops, or blackhole traffic, disrupting network connectivity.
This page as .md · .json · CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD data is provided by NIST and is public domain. Posts quoted belong to their authors.
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