{"cve":"CVE-2026-52732","nvd":{"published":"2026-08-18T20:17:16.710","modified":"2026-10-22T22:10:00.250","status":"Deferred","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.","cvss_v4":null,"cvss_v3":{"version":"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},"cwes":["CWE-770"],"references":["https://github.com/ZcashFoundation/zebra/commit/1440b43ca7df59aca948090d45117557b217a6cd","https://github.com/ZcashFoundation/zebra/releases/tag/v4.5.0","https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-4fc2-h7jh-287c","https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-4fc2-h7jh-287c"],"products":[],"source":"nvd","synced_at":"2026-10-23T16:39:26.291718493+00:00"},"epss":{"cve":"CVE-2026-52732","score":0.00507,"percentile":0.42957,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-4fc2-h7jh-287c","url":"https://osv.dev/vulnerability/GHSA-4fc2-h7jh-287c","summary":"zebrad has mempool transaction admission denial via single-peer inbound queue saturation","modified":"2026-07-02T19:56:31.667704Z","packages":[{"ecosystem":"crates.io","name":"zebrad","purl":"pkg:cargo/zebrad","ranges":["<4.5.0"],"fixed":["4.5.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}