CVE-2024-52921Network attack vector

Block propagation disruption via cross-peer state clearing

Published Nov 18, 2024 · Updated Nov 18, 2024

Missing authorization in Bitcoin Core before 25.0 allows remote attackers to hinder block propagation by sending a mutated block. An unrequested mutated block clears compact-block reconstruction and download state belonging to peers that announced the same block, so a later blocktxn response cannot complete reconstruction. Any unauthenticated P2P peer can trigger the state change; the bounded consequence is delayed block relay rather than data disclosure or modification.

CVSS severity5.3
Medium
EPSS probability0.45%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Missing authorization in Bitcoin Core before 25.0 allows remote attackers to hinder block propagation by sending a mutated block. An unrequested mutated block clears compact-block reconstruction and download state belonging to peers that announced the same block, so a later blocktxn response cannot complete reconstruction. Any unauthenticated P2P peer can trigger the state change; the bounded consequence is delayed block relay rather than data disclosure or modification.

The record

CVE
CVE-2024-52921
Published
Nov 18, 2024
Updated
Nov 18, 2024
Vendor
Bitcoin
Product
Bitcoin Core
Classifications
CWE-862, T1498
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 18, 2024CVE publishedPublication date reported by the CVE source.
  2. Nov 18, 2024Record 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=0 <25.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Bitcoin · Bitcoin Coreversion=0 <25.0

Published CVSS scores

5.3CISA-ADPCVSS: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-862Missing Authorization
T1498Network Denial of Service

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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