{"id":"CVE-2026-52732","revision":"146673b6aac947b78bdfab0656fab0c7","records":[{"revision":"146673b6aac947b78bdfab0656fab0c7","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-52732","aliases":[],"title":"ZEBRA: Mempool transaction admission denial via single-peer inbound queue saturation","description":"ZEBRA is a Zcash node written entirely in Rust. Prior to 4.5.0, one unauthenticated P2P peer can monopolize all 25 MAX_INBOUND_CONCURRENCY slots in Zebra's inbound mempool download and verification pipeline. In zebrad/src/components/mempool/downloads.rs, the bounded queue was shared globally without per-peer accounting, while peer identity was not carried through Gossip and FullQueue responses were mapped to Response::Nil instead of reaching overload disconnection handling. An attacker can advertise fake transaction identifiers and remain silent so each task holds a slot until TRANSACTION_DOWNLOAD_TIMEOUT, then periodically refill the queue as slots expire. While saturated, honest peer transactions and local sendrawtransaction requests are rejected with MempoolError::FullQueue, although block validation and synchronization continue. This issue is fixed in version 4.5.0.","state":0,"publishedAt":"2026-08-18T19:26:07.345+00:00","modifiedAt":"2026-08-18T19:32:31.103+00:00","affected":[{"ecosystem":"Vendor product","name":"zebra","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"ZcashFoundation\",\n                    \"product\": \"zebra\",\n                    \"versions\": [\n                        {\n                            \"version\": \"< 4.5.0\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","score":5.3,"severity":"MEDIUM"}],"references":["https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-4fc2-h7jh-287c","https://github.com/ZcashFoundation/zebra/commit/1440b43ca7df59aca948090d45117557b217a6cd","https://github.com/ZcashFoundation/zebra/releases/tag/v4.5.0"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-52732","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-52732","identifiers":["CVE-2026-52732"]},"retained":false,"historicalAffected":[]}],"coverage":[]}