ZEBRA: Unbounded memory leak in mempool download pipeline via timeout path cancel_handles retention

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-52734
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-08-18 20:17:17 UTC
Updated2026-08-19 19:17:18 UTC
DescriptionZEBRA is a Zcash node written entirely in Rust. Prior to 4.5.0, an unauthenticated P2P peer can cause the mempool download pipeline to retain transactions after verification reaches the outer RATE_LIMIT_DELAY timeout. In zebrad/src/components/mempool/downloads.rs, Downloads::poll_next removed cancel_handles entries after success and ordinary verification errors, but tokio::time::error::Elapsed did not carry the UnminedTxId needed to remove the timed-out entry. Each retained cancel_handles entry could hold a full Gossip::Tx(UnminedTx), while normal mined-transaction cleanup could not match attacker transactions and no periodic garbage collection or count cap existed. Sustained traffic therefore caused monotonic memory growth until swap pressure degraded the node or the operating system terminated the zebrad process for exhausting memory. This issue is fixed in version 4.5.0.

Risk And Classification

Primary CVSS: v3.1 5.3 MEDIUM from [email protected]

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS: 0.003710000 probability, percentile 0.304560000 (date 2026-08-20)

Problem Types: CWE-401 | CWE-401 CWE-401: Missing Release of Memory after Effective Lifetime

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary5.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
3.1CNADECLARED5.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA ZcashFoundation Zebra affected < 4.5.0 Not specified

References

ReferenceSourceLinkTags
github.com/ZcashFoundation/zebra/commit/1440b43ca7df59aca948090d45117557... [email protected] github.com
github.com/ZcashFoundation/zebra/releases/tag/v4.5.0 [email protected] github.com
github.com/ZcashFoundation/zebra/security/advisories/GHSA-65jj-fmw8-468q [email protected] github.com
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