{"api_version":"1","generated_at":"2026-09-27T17:09:22+00:00","cve":"CVE-2026-19655","urls":{"html":"https://cve.report/CVE-2026-19655","api":"https://cve.report/api/cve/CVE-2026-19655.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-19655","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-19655"},"summary":{"title":"On affected platforms running Arista EOS with Dynamic Host Configuration Protocol (DHCP) relay/snooping configured with the information option (Option 82), or with the DHCP server configured with match criteria based on the information option, an unauthent","description":"On affected platforms running Arista EOS with Dynamic Host Configuration Protocol (DHCP) relay/snooping configured with the information option (Option 82), or with the DHCP server configured with match criteria based on the information option, an unauthenticated attacker connected to a client-facing VLAN(s) where the relay is configured can send a specially crafted packet that causes the DHCP Relay service to restart.","state":"PUBLISHED","assigner":"Arista","published_at":"2026-09-15 21:16:36","updated_at":"2026-09-16 19:17:10"},"problem_types":["CWE-20","CWE-20 CWE-20 Improper Input 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Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-19655","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Arista Networks","product":"EOS","version":"affected 4.35.0 4.35.5M custom","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 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"]},{"source":"CNA","vendor":"Arista Networks","product":"EOS","version":"affected 4.34.0 4.34.7.1M custom","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 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"]},{"source":"CNA","vendor":"Arista Networks","product":"EOS","version":"affected 4.33.0 4.33.9M custom","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 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"]}],"timeline":[],"solutions":[{"source":"CNA","title":"","value":"The recommended resolution is to upgrade to a remediated software version at your earliest convenience. CVE-2026-19655 has been fixed in the following releases:\n\n  *  4.35.6M and later releases in the 4.35.x train\n  *  4.34.8M and later releases in the 4.34.x train\n  *  4.33.10M and later releases in the 4.33.x train","time":"","lang":"en"}],"workarounds":[{"source":"CNA","title":"","value":"There is no workaround known for this issue.","time":"","lang":"en"}],"exploits":[],"credits":[{"source":"CNA","value":"This issue was discovered internally by Arista.","lang":"en"}],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"19655","cve":"CVE-2026-19655","epss":"0.001940000","percentile":"0.093380000","score_date":"2026-09-16","updated_at":"2026-09-17 00:07:16"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"adp":[{"metrics":[{"other":{"content":{"id":"CVE-2026-19655","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","timestamp":"2026-09-16T18:02:48.292435Z","version":"2.0.3"},"type":"ssvc"}}],"providerMetadata":{"dateUpdated":"2026-09-16T18:03:27.624Z","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP"},"title":"CISA ADP Vulnrichment"}],"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 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":[{"changes":[{"at":"4.35.6M","status":"unaffected"}],"lessThanOrEqual":"4.35.5M","status":"affected","version":"4.35.0","versionType":"custom"},{"changes":[{"at":"4.34.8M","status":"unaffected"}],"lessThanOrEqual":"4.34.7.1M","status":"affected","version":"4.34.0","versionType":"custom"},{"changes":[{"at":"4.33.10M","status":"unaffected"}],"lessThanOrEqual":"4.33.9M","status":"affected","version":"4.33.0","versionType":"custom"}]}],"configurations":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"<p>In order to be vulnerable to CVE-2026-19655, any of the following conditions must be met:</p><p>1. Configure \"ip dhcp relay\" with the \"information option\" (Option 82) and at least one helper-address on an interface:</p><pre>interface Vlan100\n   ip helper-address 1.1.1.2\n   ip dhcp relay information option</pre><p>2. Configure \"ip dhcp snooping\" with the \"information option\":</p><pre>switch#show running-config | grep snooping\nip dhcp snooping\nip dhcp snooping information option\nip dhcp snooping vlan 100</pre><p>3. The DHCP server uses match criteria based on the information option, configured with \"information option arista-switch\" commands:</p><pre>dhcp server\n   client class ipv4 definition name\n      assignments\n         private-option 224 always-send type string data \"data1\"\n      !\n      match\n         information option arista-switch Ethernet55/1 vlan 100\n   !\n   subnet 1.0.0.0/24\n      range 1.0.0.1 1.0.0.5\ninterface Vlan10\n   dhcp server ipv4</pre>"}],"value":"In order to be vulnerable to CVE-2026-19655, any of the following conditions must be met:\n\n\n\n1. Configure \"ip dhcp relay\" with the \"information option\" (Option 82) and at least one helper-address on an interface:\n\n\n\ninterface Vlan100\n   ip helper-address 1.1.1.2\n   ip dhcp relay information option\n\n\n\n2. Configure \"ip dhcp snooping\" with the \"information option\":\n\n\n\nswitch#show running-config | grep snooping\nip dhcp snooping\nip dhcp snooping information option\nip dhcp snooping vlan 100\n\n\n\n3. The DHCP server uses match criteria based on the information option, configured with \"information option arista-switch\" commands:\n\n\n\ndhcp server\n   client class ipv4 definition name\n      assignments\n         private-option 224 always-send type string data \"data1\"\n      !\n      match\n         information option arista-switch Ethernet55/1 vlan 100\n   !\n   subnet 1.0.0.0/24\n      range 1.0.0.1 1.0.0.5\ninterface Vlan10\n   dhcp server ipv4"}],"credits":[{"lang":"en","type":"finder","value":"This issue was discovered internally by Arista."}],"datePublic":"2026-09-09T20:56:00.000Z","descriptions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"<p>On affected platforms running Arista EOS with Dynamic Host Configuration Protocol (DHCP) relay/snooping configured with the information option (Option 82), or with the DHCP server configured with match criteria based on the information option, an unauthenticated attacker connected to a client-facing VLAN(s) where the relay is configured can send a specially crafted packet that causes the DHCP Relay service to restart.</p>"}],"value":"On affected platforms running Arista EOS with Dynamic Host Configuration Protocol (DHCP) relay/snooping configured with the information option (Option 82), or with the DHCP server configured with match criteria based on the information option, an unauthenticated attacker connected to a client-facing VLAN(s) where the relay is configured can send a specially crafted packet that causes the DHCP Relay service to restart."}],"impacts":[{"capecId":"CAPEC-153","descriptions":[{"lang":"en","value":"CAPEC-153 Input Data Manipulation"}]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"ADJACENT_NETWORK","availabilityImpact":"HIGH","baseScore":6.5,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]},{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"NONE","attackVector":"ADJACENT","baseScore":7.1,"baseSeverity":"HIGH","exploitMaturity":"NOT_DEFINED","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"NONE","valueDensity":"NOT_DEFINED","vectorString":"CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","version":"4.0","vulnAvailabilityImpact":"HIGH","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-20","description":"CWE-20 Improper Input Validation","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-09-15T20:56:46.678Z","orgId":"c8b34d1a-69ae-45c3-88fe-f3b3d44f39b7","shortName":"Arista"},"references":[{"tags":["vendor-advisory"],"url":"https://www.arista.com/en/support/advisories-notices/security-advisory/24711-security-advisory-0155"}],"solutions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"<p>The recommended resolution is to upgrade to a remediated software version at your earliest convenience. CVE-2026-19655 has been fixed in the following releases:</p><ul><li>4.35.6M and later releases in the 4.35.x train</li><li>4.34.8M and later releases in the 4.34.x train</li><li>4.33.10M and later releases in the 4.33.x train</li></ul>"}],"value":"The recommended resolution is to upgrade to a remediated software version at your earliest convenience. CVE-2026-19655 has been fixed in the following releases:\n\n  *  4.35.6M and later releases in the 4.35.x train\n  *  4.34.8M and later releases in the 4.34.x train\n  *  4.33.10M and later releases in the 4.33.x train"}],"source":{"advisory":"155","defect":["1770194"],"discovery":"INTERNAL"},"title":"On affected platforms running Arista EOS with Dynamic Host Configuration Protocol (DHCP) relay/snooping configured with the information option (Option 82), or with the DHCP server configured with match criteria based on the information option, an unauthent","workarounds":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"<p>There is no workaround known for this issue.</p>"}],"value":"There is no workaround known for this issue."}],"x_generator":{"engine":"Vulnogram 1.0.5"}}},"cveMetadata":{"assignerOrgId":"c8b34d1a-69ae-45c3-88fe-f3b3d44f39b7","assignerShortName":"Arista","cveId":"CVE-2026-19655","datePublished":"2026-09-15T20:56:46.678Z","dateReserved":"2026-08-12T18:51:29.572Z","dateUpdated":"2026-09-16T18:03:27.624Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-15 21:16:36","lastModifiedDate":"2026-09-16 19:17:10","problem_types":["CWE-20","CWE-20 CWE-20 Improper Input Validation"],"metrics":{"cvssMetricV40":[{"source":"psirt@arista.com","type":"Secondary","cvssData":{"version":"4.0","vectorString":"CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","baseScore":7.1,"baseSeverity":"HIGH","attackVector":"ADJACENT","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","confidentialityRequirement":"NOT_DEFINED","integrityRequirement":"NOT_DEFINED","availabilityRequirement":"NOT_DEFINED","modifiedAttackVector":"NOT_DEFINED","modifiedAttackComplexity":"NOT_DEFINED","modifiedAttackRequirements":"NOT_DEFINED","modifiedPrivilegesRequired":"NOT_DEFINED","modifiedUserInteraction":"NOT_DEFINED","modifiedVulnConfidentialityImpact":"NOT_DEFINED","modifiedVulnIntegrityImpact":"NOT_DEFINED","modifiedVulnAvailabilityImpact":"NOT_DEFINED","modifiedSubConfidentialityImpact":"NOT_DEFINED","modifiedSubIntegrityImpact":"NOT_DEFINED","modifiedSubAvailabilityImpact":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED"}}],"cvssMetricV31":[{"source":"psirt@arista.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":6.5,"baseSeverity":"MEDIUM","attackVector":"ADJACENT_NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":2.8,"impactScore":3.6}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-09-16T18:02:48.292435Z","id":"CVE-2026-19655","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"19655","Ordinal":"1","Title":"On affected platforms running Arista EOS with Dynamic Host Confi","CVE":"CVE-2026-19655","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"19655","Ordinal":"1","NoteData":"On affected platforms running Arista EOS with Dynamic Host Configuration Protocol (DHCP) relay/snooping configured with the information option (Option 82), or with the DHCP server configured with match criteria based on the information option, an unauthenticated attacker connected to a client-facing VLAN(s) where the relay is configured can send a specially crafted packet that causes the DHCP Relay service to restart.","Type":"Description","Title":"On affected platforms running Arista EOS with Dynamic Host Confi"}]}}}