---
id: "CVE-2026-121367"
page: "https://infrastack.ai/live/CVE-2026-121367"
kind: "vulnerability"
aliases: ["CVE-2026-121367"]
title: "Arista EOS: RIPv2 silently enabled on management interfaces accepts unauthenticated routes"
severity: "critical"
cvss: 9.6
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["arista-eos", "infrastructure", "network", "ripv2"]
not_affected_if: ["ripv2-not-configured"]
published_at: "2026-11-10T20:18:55+00:00"
first_seen_at: "2026-11-10T20:46:04+00:00"
updated_at: "2026-11-10T20:49:55+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-121367", "first_seen_at": "2026-11-10T20:46:04+00:00"}, {"source": "analyst", "url": null, "first_seen_at": "2026-11-10T20:49:55+00:00"}]
exploit_sources: []
---

# Arista EOS: RIPv2 silently enabled on management interfaces accepts unauthenticated routes

Link for people: https://infrastack.ai/live/CVE-2026-121367 (this .md is for agents)

On some Arista EOS platforms with RIPv2 configured, RIPv2 can be enabled on management interfaces even when disabled in config. An attacker on the adjacent network can send crafted RIPv2 advertisements that the device installs without authentication, redirecting or blackholing traffic.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check whether RIP is configured: 'show running-config section router rip' on the EOS device; if there is no router rip configuration, the NVD text gives no exposure path.
- Affected and fixed EOS releases: unknown until Arista's advisory for CVE-2026-121367 is found. Compare your 'show version' output against it.

## Timeline

- 2026-11-10T20:46:04+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-121367
- 2026-11-10T20:49:55+00:00 analyst — Arista advisory for this CVE not found (published today; arista.com advisories page is behind a client challenge, searches show only other 2026 advisories). Only NVD text available; no affected/fixed EOS versions, no workaround. Revisit when the Arista Security Advisory is indexed (check arista.com/en/support/advisories-notices).

## From the sources

On affected Arista EOS platforms with Routing Information Protocol version 2 (RIPv2) configured, under certain conditions, RIPv2 might be silently enabled on management interfaces even when the RIP agent intends to disable it. It allows an unauthenticated attacker with access to the adjacent network to send crafted RIPv2 route advertisements to the device's management IP address. The device could accept and install those routes without authentication.

Successful exploitation could allow the attacker to redirect traffic flows to an attacker-controlled destination, install more-specific routes that blackhole legitimate traffic, or otherwise disrupt network reachability for systems whose traffic passes through the affected device.

---

_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_