{"schema":"threatline.record/2","record":{"id":"CVE-2025-53521","aliases":[],"summary":"F5 BIG-IP Stack-Based Buffer Overflow Vulnerability","details":"F5 BIG-IP APM contains a stack-based buffer overflow vulnerability that could allow a threat actor to achieve remote code execution.","categories":["Network & edge"],"product":"BIG-IP","vendor":"F5","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2025-53521","source_modified_at":"2026-03-31T16:04:27.360Z","fetched_at":"2026-10-23T18:42:43.628194Z","product":"BIG-IP","vendor":"F5","versions":[{"status":"affected","version":"17.5.0","lessThan":"17.5.1.3","versionType":"custom"},{"status":"affected","version":"17.1.0","lessThan":"17.1.3","versionType":"custom"},{"status":"affected","version":"16.1.0","lessThan":"16.1.6.1","versionType":"custom"},{"status":"affected","version":"15.1.0","lessThan":"15.1.10.8","versionType":"custom"}],"defaultStatus":"unknown"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2025-53521","source_modified_at":"2026-03-31T16:04:27.360Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"name":"BIG-IP","ecosystem":null},"version":"17.5.1.3","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2025-53521","source_modified_at":"2026-03-31T16:04:27.360Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"name":"BIG-IP","ecosystem":null},"version":"17.1.3","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2025-53521","source_modified_at":"2026-03-31T16:04:27.360Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"name":"BIG-IP","ecosystem":null},"version":"16.1.6.1","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2025-53521","source_modified_at":"2026-03-31T16:04:27.360Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"name":"BIG-IP","ecosystem":null},"version":"15.1.10.8","basis":"first unaffected version stated in the CVE record"}],"cvss":9.8,"severity":"Critical","kev":{"listed":true,"date_added":"2026-03-27","due_date":"2026-03-30","required_action":"Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.","ransomware_campaign_use":"Unknown"},"epss":{"probability":0.02295,"percentile":0.8314,"score_date":"2026-10-23"},"published_at":"2025-10-15T13:55:52.694Z","modified_at":"2026-03-31T16:04:27.360Z","provenance":[{"source":"CISA KEV","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23T17:00:09.9001Z"},{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2025-53521","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-03-31T16:04:27.360Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2025-53521","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CISA KEV","CVE List","EPSS"],"references":[{"url":"https://my.f5.com/manage/s/article/K000160486","source":"CISA KEV"},{"url":"https://my.f5.com/manage/s/article/K11438344","source":"CISA KEV"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-53521","source":"CISA KEV"},{"source":"CVE List","url":"https://my.f5.com/manage/s/article/K000156741","tags":["vendor-advisory"]},{"source":"CVE List","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-53521","tags":["government-resource"]}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","ssvc":{"exploitation":"active","automatable":"yes","technical_impact":"total","assessed_at":"2026-03-28T03:55:47.100165Z"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-03-31T16:04:27.360Z","content_hash":"897e36d85d9f484f3560000a64bb0590816f337716101074acdbe2b128d9c333"}}