CVE-2026-121288 (GCVE-0-2026-121288)

Vulnerability from cvelistv5 – Published: 2026-11-10 20:09 – Updated: 2026-11-10 20:09
VLAI
Title
Security Advisory 0221
Summary
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
8.1 (High)
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
6.1 (Medium)
CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:L/SA:L
CWE
  • CWE-303 - Incorrect Implementation of Authentication Algorithm
Assigner
Arista CNA
References
Impacted products
Vendor Product Version
Arista Networks EOS Affected: 4.37.0F (custom)
Affected: 4.36.0F , ≤ 4.36.2F (custom)
Affected: 4.35.0F , ≤ 4.35.6M (custom)
Affected: 4.34.0F , ≤ 4.34.8M (custom)
Affected: 4.33.0F , ≤ 4.33.10M (custom)
Affected: 4.32.0F , < 4.33.0F (custom)
Affected: 1.0.0 , < 4.32.0F (custom)
Create a notification for this product.
Credits
Arista would like to acknowledge and thank Joshua Foote from the XOR team at JP Morgan Chase for responsibly reporting CVE-2026-121288.
Show details on NVD website
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "platforms": [
            "710 Series",
            "720D Series",
            "720XP/722XPM Series",
            "750X Series",
            "7010TX Series",
            "7020R/R4 Series",
            "7130 Series running EOS",
            "7170 Series",
            "7050X3/X4 Series",
            "7060X/X2/X4/X5/X6/XE7 Series",
            "7260X/X3 Series",
            "7280R/R2/R3/R4 Series",
            "7300X/X3 Series",
            "7320X Series",
            "7358X4 Series",
            "7368X4 Series",
            "7388X5 Series",
            "7500R/R2/R3 Series",
            "7800R3/R4 Series",
            "7700R4 Series",
            "AWE 5000 Series",
            "AWE 7200R Series",
            "CloudEOS",
            "cEOS-lab",
            "vEOS-lab",
            "CloudVision eXchange, virtual or physical appliance"
          ],
          "product": "EOS",
          "vendor": "Arista Networks",
          "versions": [
            {
              "status": "affected",
              "version": "4.37.0F",
              "versionType": "custom"
            },
            {
              "lessThanOrEqual": "4.36.2F",
              "status": "affected",
              "version": "4.36.0F",
              "versionType": "custom"
            },
            {
              "lessThanOrEqual": "4.35.6M",
              "status": "affected",
              "version": "4.35.0F",
              "versionType": "custom"
            },
            {
              "lessThanOrEqual": "4.34.8M",
              "status": "affected",
              "version": "4.34.0F",
              "versionType": "custom"
            },
            {
              "lessThanOrEqual": "4.33.10M",
              "status": "affected",
              "version": "4.33.0F",
              "versionType": "custom"
            },
            {
              "lessThan": "4.33.0F",
              "status": "affected",
              "version": "4.32.0F",
              "versionType": "custom"
            },
            {
              "lessThan": "4.32.0F",
              "status": "affected",
              "version": "1.0.0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "configurations": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cpre\u003eswitch# show running-config | section router rip\nrouter rip\n   no shutdown\n   network 192.0.2.0/24\n\nswitch# show running-config interfaces Ethernet1\ninterface Ethernet1\n   ip address 192.0.2.1/24 \n   rip authentication algorithm md5 tx key-id 10\u003c/pre\u003e"
            }
          ],
          "value": "switch# show running-config | section router rip\nrouter rip\n   no shutdown\n   network 192.0.2.0/24\n\nswitch# show running-config interfaces Ethernet1\ninterface Ethernet1\n   ip address 192.0.2.1/24 \n   rip authentication algorithm md5 tx key-id 10"
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "reporter",
          "value": "Arista would like to acknowledge and thank Joshua Foote from the XOR team at JP Morgan Chase for responsibly reporting CVE-2026-121288."
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "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."
        }
      ],
      "impacts": [
        {
          "capecId": "CAPEC-115",
          "descriptions": [
            {
              "lang": "en",
              "value": "CAPEC-115 Authentication Bypass"
            }
          ]
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 8.1,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H",
            "version": "3.1"
          }
        },
        {
          "cvssV4_0": {
            "baseScore": 6.1,
            "baseSeverity": "MEDIUM",
            "vectorString": "CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:L/SA:L",
            "version": "4.0"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-303",
              "description": "CWE-303 Incorrect Implementation of Authentication Algorithm",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-11-10T20:09:56.336Z",
        "orgId": "c8b34d1a-69ae-45c3-88fe-f3b3d44f39b7",
        "shortName": "Arista"
      },
      "references": [
        {
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://www.arista.com/en/support/advisories-notices/security-advisory/25043-security-advisory-0221"
        }
      ],
      "source": {
        "advisory": "Security Advisory 0221",
        "defects": [
          "1985547"
        ],
        "discovery": "EXTERNAL"
      },
      "title": "Security Advisory 0221",
      "workarounds": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cpre\u003eswitch(config)# router rip\nswitch(config-router-rip)# shutdown\nswitch(config-router-rip)# end\n\nNote: disabling RIP or changing network statements may withdraw routes and interrupt connectivity. Plan a change window, confirm alternate routing, and verify the resulting configuration and route behavior.\u003c/pre\u003e"
            }
          ],
          "value": "switch(config)# router rip\nswitch(config-router-rip)# shutdown\nswitch(config-router-rip)# end\n\nNote: disabling RIP or changing network statements may withdraw routes and interrupt connectivity. Plan a change window, confirm alternate routing, and verify the resulting configuration and route behavior."
        }
      ]
    }
  },
  "cveMetadata": {
    "assignerOrgId": "c8b34d1a-69ae-45c3-88fe-f3b3d44f39b7",
    "assignerShortName": "Arista",
    "cveId": "CVE-2026-121288",
    "datePublished": "2026-11-10T20:09:56.336Z",
    "dateReserved": "2026-11-03T11:21:01.891Z",
    "dateUpdated": "2026-11-10T20:09:56.336Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}



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