{"schema_version":"public-product-v1.1","generated_at":"2026-07-21T10:39:52Z","exposure_verdict":"not_assessed","verdict_reason":"Public evidence does not evaluate exact release, platform, enabled features, configuration, compensating controls, or live exposure.","advisory":{"id":"cisco-sa-ipv6-acl-CHgdYk8j","slug":"cisco-sa-ipv6-acl-chgdyk8j","vendor":"Cisco","title":"Cisco IOS XR and Cisco NX-OS Software IPv6 Access Control List Bypass Vulnerability","summary":"A vulnerability in the IPv6 traffic processing of Cisco IOS XR Software and Cisco NX-OS Software for certain Cisco devices could allow an unauthenticated, remote attacker to bypass an IPv6 access control list (ACL) that is configured for an interface of an affected device. The vulnerability is due to improper processing of IPv6 traffic that is sent through an affected device. An attacker could exploit this vulnerability by sending crafted IPv6 packets that traverse the affected device. A successful exploit could allow the attacker to access resources that would typically be protected by the interface ACL. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is available at the following link:https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ipv6-acl-CHgdYk8j","severity":"Medium","published_at":"2021-02-03T16:00:00Z","updated_at":"2021-02-03T16:00:00Z","source_url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ipv6-acl-CHgdYk8j","csaf_url":"https://sec.cloudapps.cisco.com/security/center/contentjson/CiscoSecurityAdvisory/cisco-sa-ipv6-acl-CHgdYk8j/csaf/cisco-sa-ipv6-acl-CHgdYk8j.json","exposure_verdict":"not_assessed","verdict_reason":"Public evidence does not evaluate exact release, platform, enabled features, configuration, compensating controls, or live exposure."},"freshness":{"last_source_refreshed_at":"2026-07-21T05:16:34Z","latest_source_refresh_at":"2026-07-21T05:16:34Z","oldest_source_refresh_at":"2026-07-21T03:00:03Z","all_sources_fresh":true,"sources":[{"source":"cisco_advisories","label":"Cisco advisories","last_success_at":"2026-07-21T03:00:03Z","stale":false},{"source":"cisco_csaf","label":"Cisco CSAF","last_success_at":"2026-07-21T05:14:24Z","stale":false},{"source":"nvd_cves","label":"NVD CVEs","last_success_at":"2026-07-21T05:16:30Z","stale":false},{"source":"cisa_kev","label":"CISA KEV","last_success_at":"2026-07-21T05:16:31Z","stale":false},{"source":"first_epss","label":"EPSS","last_success_at":"2026-07-21T05:16:34Z","stale":false}]},"summary":{"cve_count":1,"visible_product_count":4,"public_evidence_count":4,"kev_count":0,"highest_epss":0.01222},"cves":[{"id":"CVE-2021-1389","kev":false,"epss":{"score":0.01222,"percentile":0.65389,"score_date":"2026-07-20","updated_at":"2026-07-21T05:16:34Z"}}],"public_evidence":[{"product":{"name":"Cisco IOS XR Software","slug":"cisco-ios-xr-software","vendor":"Cisco"},"cve":{"id":"CVE-2021-1389"},"evidence_type":"structured_affected","evidence_label":{"scope":"CSAF product evidence","label":"product_status known affected"},"evidence_source":"Cisco CSAF","source":"Cisco CSAF","source_document_fetched_at":"2026-07-20T04:13:07Z","csaf_status":"known_affected","csaf_product_status":"known_affected","csaf_product_status_path":"vulnerabilities[].product_status.known_affected","raw_product_name":"Cisco IOS XR Software","exposure_verdict":"not_assessed","verdict_reason":"Public evidence does not evaluate exact release, platform, enabled features, configuration, compensating controls, or live exposure.","exposure_verdict_reason":"Public evidence does not evaluate exact release, platform, enabled features, configuration, compensating controls, or live exposure.","kev":false,"epss":{"score":0.01222,"score_date":"2026-07-20","updated_at":"2026-07-21T05:16:34Z"},"published_at":"2021-02-03T16:00:00Z","updated_at":"2021-02-03T16:00:00Z","advisory_updated_at":"2021-02-03T16:00:00Z","source_url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ipv6-acl-CHgdYk8j","remediation":{"url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ipv6-acl-CHgdYk8j"},"row_display_order":1},{"product":{"name":"Cisco Nexus 3000 Series Switches","slug":"cisco-nexus-3000-series-switches","vendor":"Cisco"},"cve":{"id":"CVE-2021-1389"},"evidence_type":"structured_affected","evidence_label":{"scope":"CSAF product evidence","label":"product_status known affected"},"evidence_source":"Cisco CSAF","source":"Cisco CSAF","source_document_fetched_at":"2026-07-20T04:13:07Z","csaf_status":"known_affected","csaf_product_status":"known_affected","csaf_product_status_path":"vulnerabilities[].product_status.known_affected","raw_product_name":"Cisco NX-OS Software 7.0(3)F3(1) when installed on Cisco Nexus 3000 Series Switches; Cisco NX-OS Software 7.0(3)F3(2) when installed on Cisco Nexus 3000 Series Switches; Cisco NX-OS Software 7.0(3)F3(3) when installed on Cisco Nexus 3000 Series Switches; Cisco NX-OS Software 7.0(3)F3(3a) when installed on Cisco Nexus 3000 Series Switches; Cisco NX-OS Software 7.0(3)F3(3c) when installed on Cisco Nexus 3000 Series Switches; Cisco NX-OS Software 7.0(3)F3(4) when installed on Cisco Nexus 3000 Series Switches; Cisco NX-OS Software 7.0(3)F3(5) when installed on Cisco Nexus 3000 Series Switches; Cisco NX-OS Software 9.2(1) when installed on Cisco Nexus 3000 Series Switches; Cisco NX-OS Software 9.2(2) when installed on Cisco Nexus 3000 Series Switches; Cisco NX-OS Software 9.2(2t) when installed on Cisco Nexus 3000 Series Switches; Cisco NX-OS Software 9.2(2v) when installed on Cisco Nexus 3000 Series Switches; Cisco NX-OS Software 9.2(3) when installed on Cisco Nexus 3000 Series Switches; Cisco NX-OS Software 9.2(3y) when installed on Cisco Nexus 3000 Series Switches; Cisco NX-OS Software 9.2(4) when installed on Cisco Nexus 3000 Series Switches; Cisco NX-OS Software 9.3(1) when installed on Cisco Nexus 3000 Series Switches; Cisco NX-OS Software 9.3(2) when installed on Cisco Nexus 3000 Series Switches; Cisco NX-OS Software 9.3(3) when installed on Cisco Nexus 3000 Series Switches; Cisco NX-OS Software 9.3(4) when installed on Cisco Nexus 3000 Series Switches; Cisco NX-OS Software 9.3(5) when installed on Cisco Nexus 3000 Series Switches; Cisco NX-OS Software 9.3(5w) when installed on Cisco Nexus 3000 Series Switches","exposure_verdict":"not_assessed","verdict_reason":"Public evidence does not evaluate exact release, platform, enabled features, configuration, compensating controls, or live exposure.","exposure_verdict_reason":"Public evidence does not evaluate exact release, platform, enabled features, configuration, compensating controls, or live exposure.","kev":false,"epss":{"score":0.01222,"score_date":"2026-07-20","updated_at":"2026-07-21T05:16:34Z"},"published_at":"2021-02-03T16:00:00Z","updated_at":"2021-02-03T16:00:00Z","advisory_updated_at":"2021-02-03T16:00:00Z","source_url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ipv6-acl-CHgdYk8j","remediation":{"url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ipv6-acl-CHgdYk8j"},"row_display_order":2},{"product":{"name":"Cisco Nexus 9000 Series Switches","slug":"cisco-nexus-9000-series-switches","vendor":"Cisco"},"cve":{"id":"CVE-2021-1389"},"evidence_type":"structured_affected","evidence_label":{"scope":"CSAF product evidence","label":"product_status known affected"},"evidence_source":"Cisco CSAF","source":"Cisco CSAF","source_document_fetched_at":"2026-07-20T04:13:07Z","csaf_status":"known_affected","csaf_product_status":"known_affected","csaf_product_status_path":"vulnerabilities[].product_status.known_affected","raw_product_name":"Cisco NX-OS Software 7.0(3)F3(1) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS Software 7.0(3)F3(3) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS Software 7.0(3)F3(3a) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS Software 7.0(3)F3(3c) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS Software 7.0(3)F3(4) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS Software 7.0(3)F3(5) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS Software 9.2(1) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS Software 9.2(2) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS Software 9.2(3) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS Software 9.2(3y) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS Software 9.2(4) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS Software 9.3(1) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS Software 9.3(1z) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS Software 9.3(2) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS Software 9.3(3) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS Software 9.3(4) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS Software 9.3(5) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS Software 9.3(5w) when installed on Cisco Nexus 9000 Series Switches","exposure_verdict":"not_assessed","verdict_reason":"Public evidence does not evaluate exact release, platform, enabled features, configuration, compensating controls, or live exposure.","exposure_verdict_reason":"Public evidence does not evaluate exact release, platform, enabled features, configuration, compensating controls, or live exposure.","kev":false,"epss":{"score":0.01222,"score_date":"2026-07-20","updated_at":"2026-07-21T05:16:34Z"},"published_at":"2021-02-03T16:00:00Z","updated_at":"2021-02-03T16:00:00Z","advisory_updated_at":"2021-02-03T16:00:00Z","source_url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ipv6-acl-CHgdYk8j","remediation":{"url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ipv6-acl-CHgdYk8j"},"row_display_order":3},{"product":{"name":"Cisco NX-OS Software","slug":"cisco-nx-os-software","vendor":"Cisco"},"cve":{"id":"CVE-2021-1389"},"evidence_type":"structured_affected","evidence_label":{"scope":"CSAF product evidence","label":"product_status known affected"},"evidence_source":"Cisco CSAF","source":"Cisco CSAF","source_document_fetched_at":"2026-07-20T04:13:07Z","csaf_status":"known_affected","csaf_product_status":"known_affected","csaf_product_status_path":"vulnerabilities[].product_status.known_affected","raw_product_name":"10.2(3v); 10.3(3o); 10.3(3p); 10.3(3q); 10.3(3r); 10.3(3w); 10.3(3x); 10.3(4g); 10.3(4h); 10.3(99w); 10.3(99x)","exposure_verdict":"not_assessed","verdict_reason":"Public evidence does not evaluate exact release, platform, enabled features, configuration, compensating controls, or live exposure.","exposure_verdict_reason":"Public evidence does not evaluate exact release, platform, enabled features, configuration, compensating controls, or live exposure.","kev":false,"epss":{"score":0.01222,"score_date":"2026-07-20","updated_at":"2026-07-21T05:16:34Z"},"published_at":"2021-02-03T16:00:00Z","updated_at":"2021-02-03T16:00:00Z","advisory_updated_at":"2021-02-03T16:00:00Z","source_url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ipv6-acl-CHgdYk8j","remediation":{"url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ipv6-acl-CHgdYk8j"},"row_display_order":4}]}