CVE-2026-121367 (CVSS 9.6)

Description

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.

Is your site exposed to CVE-2026-121367?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

9.6

CRITICAL

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:H

Weakness Type (CWE)

CWE-440 CWE-440

References

Other References

https://www.arista.com/en/support/advisories-notices/security-advisory/25042-security-advisory-0220

Frequently Asked Questions

What is CVE-2026-121367? +

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. It has a CVSS v3.1 base score of 9.6 (CRITICAL).

How severe is CVE-2026-121367? +

CVE-2026-121367 has a CVSS v3.1 score of 9.6 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately.

How do I check if I'm vulnerable to CVE-2026-121367? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-97687

urllib3 is an HTTP client library for Python. From 1.26.0 until 2.8.0, the proxy_ssl_context, proxy_assert_hostname, proxy_assert_fingerprint, ssl_context, cert_reqs, verify_mode, use_forwarding_for_https=True, …

CVE-2025-62621

Expected behavior violation in AMD Secure Encrypted Virtualization (SEV) firmware could allow a malicious hypervisor to bypass Reverse Map Table …

CVE-2026-16769

An unencrypted 'pause encryption request' message causes a denial of service in the in the RS9116W/SiWx917. See vulnerability B-E10 in …

CVE-2024-32971 9.0

Apollo Router is a configurable, graph router written in Rust to run a federated supergraph that uses Apollo Federation 2. …

CVE-2026-93675 8.8

IBM Langflow OSS 1.0.0 through 1.12.2 could allow a remote attacker to execute arbitrary code due to an expected dependency …

CVE-2025-8850 8.8

In danny-avila/librechat version 0.7.9, there is an insecure API design issue in the 2-Factor Authentication (2FA) flow. The system allows …

CVE-2026-121367