{"schema_version":"public-product-v1.1","generated_at":"2026-07-21T11:04:24Z","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-lnt-L9zOkBz5","slug":"cisco-sa-lnt-l9zokbz5","vendor":"Cisco","title":"Cisco IOS XR Software Image Verification Vulnerability","summary":"A vulnerability in Cisco IOS XR Software image verification checks could allow an authenticated, local attacker to execute arbitrary code on the underlying operating system. This vulnerability is due to a time-of-check, time-of-use (TOCTOU) race condition when an install query regarding an ISO image is performed during an install operation that uses an ISO image. An attacker could exploit this vulnerability by modifying an ISO image and then carrying out install requests in parallel. A successful exploit could allow the attacker to execute arbitrary code on an affected device. 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-lnt-L9zOkBz5 This advisory is part of the September 2023 release of the Cisco IOS XR Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see Cisco Event Response: September 2023 Semiannual Cisco IOS XR Software Security Advisory Bundled Publication.","severity":"Medium","published_at":"2023-09-13T16:00:00Z","updated_at":"2023-09-13T16:00:00Z","source_url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-lnt-L9zOkBz5","csaf_url":"https://sec.cloudapps.cisco.com/security/center/contentjson/CiscoSecurityAdvisory/cisco-sa-lnt-L9zOkBz5/csaf/cisco-sa-lnt-L9zOkBz5.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":1,"public_evidence_count":1,"kev_count":0,"highest_epss":0.00088},"cves":[{"id":"CVE-2023-20135","kev":false,"epss":{"score":0.00088,"percentile":0.00489,"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-2023-20135"},"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":"2026-07-20T03:58:05Z","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":0.00088,"score_date":"2026-07-20","updated_at":"2026-07-21T05:16:34Z"},"published_at":"2023-09-13T16:00:00Z","updated_at":"2023-09-13T16:00:00Z","advisory_updated_at":"2023-09-13T16:00:00Z","source_url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-lnt-L9zOkBz5","remediation":{"url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-lnt-L9zOkBz5"},"row_display_order":1}]}