{"schema":"threatline.record/2","record":{"id":"CVE-2026-109366","aliases":["GHSA-4f6v-mj46-gxg3"],"summary":"Zebra before 6.4.0 Gossiped Block Drop via Forged Coinbase scriptSig Height","details":"Zebra before 6.4.0 contains an improper integrity validation vulnerability in the inbound gossip download path that allows unauthenticated peers to force dropping of new blocks without penalty. Attackers can serve a real block with a coinbase scriptSig rewritten to height 1, which keeps the ZIP-244 block hash, triggering a behind-tip drop before consensus validation and delaying tip discovery for mining backends.","categories":["Unclassified"],"product":"zebra","vendor":"ZcashFoundation","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-109366","source_modified_at":"2026-10-12T16:05:43.620Z","fetched_at":"2026-10-23T18:48:36.087640Z","product":"zebra","vendor":"ZcashFoundation","versions":[{"version":"0","status":"affected","versionType":"semver","lessThan":"6.4.0"},{"version":"6.4.0","status":"unaffected","versionType":"semver"}],"defaultStatus":"unaffected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-109366","source_modified_at":"2026-10-12T16:05:43.620Z","fetched_at":"2026-10-23T18:48:36.087640Z","package":{"name":"zebra","ecosystem":null},"version":"6.4.0","basis":"first unaffected version stated in the CVE record"}],"cvss":6.3,"severity":"Medium","kev":{"listed":false},"epss":{"probability":0.00157,"percentile":0.04484,"score_date":"2026-10-23"},"published_at":"2026-10-12T16:05:43.620Z","modified_at":"2026-10-12T16:05:43.620Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-109366","fetched_at":"2026-10-23T18:48:36.087640Z","source_modified_at":"2026-10-12T16:05:43.620Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-109366","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-4f6v-mj46-gxg3","tags":["vendor-advisory"]},{"source":"CVE List","url":"https://www.vulncheck.com/advisories/zebra-before-6.4.0-gossiped-block-drop-via-forged-coinbase-scriptsig-height","tags":["third-party-advisory"]}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":null,"confidence":"unknown","reviewed":false},"change_timestamp":"2026-10-12T16:05:43.620Z","content_hash":"a12671ee0ad522a92ff792f6b20f48a6aeb0bc7c1b0d730c6b42752e3ccc7e3d"}}