CVSS 4.0
6.1 mediumCVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:L/SA:LCVE-2026-121288 Security Advisory 0221
Medium (6.1) in arista networks eos. EPSS 0.2% estimated probability of exploitation activity in the next 30 days.
On this page
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.
Severity
CVSS 3.1
8.1 highCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H- EPSS
- 0.2% estimated probability of exploitation activity in the next 30 days; 15th percentile. Scored 2026-11-13. A forecast for this CVE across the internet, not for your own systems.
- CISA's assessment (SSVC)
- Exploitation: none · Automatable: no · Technical impact: partial, assessed 2026-11-13. From CISA's Vulnrichment in the CVE List: whether it is exploited, whether exploiting it can be automated, and how much control it gives.
- CWE
- CWE-303 Incorrect Implementation of Authentication Algorithm
- OWASP Top 10
- A07:2025 Authentication Failures
- Published
- Modified
- Assigned by
- Arista (CNA)
- NVD analysis
- Awaiting analysis
- Record from
- the NVD, synced
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Affected
- arista networks:eos
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| Arista Networks EOS | 4.37.0F |
| Arista Networks EOS | from 4.36.0F through 4.36.2F |
| Arista Networks EOS | from 4.35.0F through 4.35.6M |
| Arista Networks EOS | from 4.34.0F through 4.34.8M |
| Arista Networks EOS | from 4.33.0F through 4.33.10M |
| Arista Networks EOS | from 4.32.0F before 4.33.0F |
| Arista Networks EOS | from 1.0.0 before 4.32.0F |
Attack patterns (CAPEC)
- CAPEC-90 Reflection Attack in Authentication Protocol Likelihood: High · Severity: High
The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits.