{"id":"CVE-2026-109366","aliases":["EUVD-2026-97668","GHSA-4f6v-mj46-gxg3","GHSA-mprq-2cjh-7qc2"],"status":"published","title":"Zebra before 6.4.0 Gossiped Block Drop via Forged Coinbase scriptSig Height","description":"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.","severity":{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00157,"percentile":0.04882,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-354"],"published":"2026-10-12T16:05:43Z","modified":"2026-10-28T02:30:55Z","products":[{"vendor":"zcashfoundation","product":"zebra"}],"references":[{"url":"https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-4f6v-mj46-gxg3","tags":["vendor-advisory","exploit","advisory"]},{"url":"https://www.vulncheck.com/advisories/zebra-before-6.4.0-gossiped-block-drop-via-forged-coinbase-scriptsig-height","tags":["third-party-advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-109366","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-mprq-2cjh-7qc2"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/109xxx/CVE-2026-109366.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-109366","title":"Zebra before 6.4.0 Gossiped Block Drop via Forged Coinbase scriptSig Height","description":"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.","status":"published","published":"2026-10-12T16:05:43.62Z","modified":"2026-10-26T20:37:40.885Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium","assessor":"cna"},{"version":"3.1","score":3.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"low","assessor":"cna"}],"cwes":["CWE-354"],"updated_at":"2026-11-02T14:20:11.581788Z"}],"euvd":[{"id":"EUVD-2026-97668","description":"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.","status":"published","published":"2026-10-12T16:05:43Z","modified":"2026-10-26T20:37:40Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-02T16:59:27.138919Z"}],"ghsa":[{"id":"GHSA-mprq-2cjh-7qc2","title":"Zebra before 6.4.0 contains an improper integrity validation vulnerability in the inbound gossip...","description":"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.","status":"published","published":"2026-10-12T18:31:54Z","modified":"2026-10-12T18:31:58Z","cvss":[{"version":"3.1","score":3.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"low"},{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/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","level":"medium"}],"cwes":["CWE-354"],"updated_at":"2026-11-02T15:13:07.940274Z"}],"nvd":[{"id":"CVE-2026-109366","description":"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.","status":"published","published":"2026-10-12T17:17:34.393Z","modified":"2026-10-26T21:17:28.143Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/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","level":"medium","assessor":"secondary"},{"version":"3.1","score":3.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"low","assessor":"secondary"}],"cwes":["CWE-354"],"updated_at":"2026-11-02T14:12:56.310333Z"}],"osv":[{"id":"CVE-2026-109366","title":"Zebra before 6.4.0 Gossiped Block Drop via Forged Coinbase scriptSig Height","description":"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.","status":"published","published":"2026-10-12T16:05:43.62Z","modified":"2026-10-28T02:30:55.478739791Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-354"],"updated_at":"2026-11-02T15:44:55.279797Z"}]}}