CVE-2026-52734Network attack vector

Memory exhaustion via timeout-path handle retention

Published Aug 18, 2026 · Updated Aug 19, 2026

Memory exhaustion in Zcash Foundation Zebra before 4.5.0 allows remote attackers to interrupt node service via crafted P2P transactions. In zebrad/src/components/mempool/downloads.rs, Downloads::poll_next leaves timed-out cancel_handles entries in memory because the outer RATE_LIMIT_DELAY timeout returns tokio::time::error::Elapsed without the UnminedTxId needed to remove the retained transaction state. Exposure requires only unauthenticated peer connectivity to a node with its mempool enabled; sustained traffic can drive unbounded RAM growth until swap pressure degrades the node or the operating system kills zebrad.

CVSS severity5.3
Medium
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory exhaustion in Zcash Foundation Zebra before 4.5.0 allows remote attackers to interrupt node service via crafted P2P transactions. In zebrad/src/components/mempool/downloads.rs, Downloads::poll_next leaves timed-out cancel_handles entries in memory because the outer RATE_LIMIT_DELAY timeout returns tokio::time::error::Elapsed without the UnminedTxId needed to remove the retained transaction state. Exposure requires only unauthenticated peer connectivity to a node with its mempool enabled; sustained traffic can drive unbounded RAM growth until swap pressure degrades the node or the operating system kills zebrad.

The record

CVE
CVE-2026-52734
Published
Aug 18, 2026
Updated
Aug 19, 2026
Vendor
Zcash Foundation
Product
Zebra
Classifications
CWE-401, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 4.5.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Zcash Foundation · Zebraversion=< 4.5.0

Published CVSS scores

5.3GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-401Missing Release of Memory after Effective Lifetime
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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