CVE-2024-35202Network attack vector

Remote node crash via repeated FillBlock call

Published Oct 10, 2024 · Updated Oct 10, 2024

Denial of service in Bitcoin Core before 25.0 allows remote attackers to crash a node through a crafted blocktxn message. The blocktxn handler leaves the PartiallyDownloadedBlock and request state intact after a merkle-root mismatch, allowing a second FillBlock call to violate its single-use assertion. Any network peer can trigger the path without authentication by supplying transactions absent from the announced block, terminating the node process.

CVSS severity7.5
High
EPSS probability0.89%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Bitcoin Core before 25.0 allows remote attackers to crash a node through a crafted blocktxn message. The blocktxn handler leaves the PartiallyDownloadedBlock and request state intact after a merkle-root mismatch, allowing a second FillBlock call to violate its single-use assertion. Any network peer can trigger the path without authentication by supplying transactions absent from the announced block, terminating the node process.

The record

CVE
CVE-2024-35202
Published
Oct 10, 2024
Updated
Oct 10, 2024
Vendor
Bitcoin
Product
Bitcoin Core
Classifications
CWE-770, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 10, 2024CVE publishedPublication date reported by the CVE source.
  2. Oct 10, 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

7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-770Allocation of Resources Without Limits or Throttling
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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