CVE-2026-52732

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 v3 5.3 MEDIUM

5.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 3.9 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact LOW

Scope UNCHANGED

References

Link	Resource
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

Configurations

No configuration.

History

No history.

Information

Published : 2026-08-18 20:17

Updated : 2026-09-09 21:13

NVD link : CVE-2026-52732

Mitre link : CVE-2026-52732

CVE.ORG link : CVE-2026-52732

JSON object : View

Products Affected

No product.

CWE

CWE-770

Allocation of Resources Without Limits or Throttling

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