CVE-2026-121288

HIGHCVSS 8.1/10EPSS 0.24%

Last modified

CVE-2026-121288 is a high-severity vulnerability rated 8.1/10 on the CVSS scale. 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. EPSS estimates a 0.24% chance of exploitation in the next 30 days.

Description

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.

Metrics

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
Arista NetworksEOS4.37.0F; >= 4.36.0F, <= 4.36.2F; >= 4.35.0F, <= 4.35.6M; >= 4.34.0F, <= 4.34.8M; >= 4.33.0F, <= 4.33.10M; >= 4.32.0F, < 4.33.0F; >= 1.0.0, < 4.32.0F

References

Timeline

Published
Last Modified
Status
Awaiting Analysis

Frequently Asked Questions

What is 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.
How severe is CVE-2026-121288?
CVE-2026-121288 has a CVSS score of 8.1/10 (HIGH severity). The EPSS model estimates a 0.24% probability of exploitation in the next 30 days.
How do I fix CVE-2026-121288?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST