Vulnerability in Arista Networks Eos
CVE-2026-121288
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.
Published .
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Arista Networks Eos — versions 4.37.0F
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-121288?
- CVE-2026-121288 is a high-severity vulnerability in Arista Networks Eos, classified under Incorrect Implementation of Authentication Algorithm. CVSS score: 8.1/10. Published 2026-11-10.
- How severe is CVE-2026-121288?
- High severity. CVSS v3 base score is 8.1 out of 10.