How severe is CVE-2019-25220?

CVE-2019-25220 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2019-25220 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2019-25220?

CVE-2019-25220 affects Bitcoin Bitcoin Core. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2019-25220?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2019-25220 have an EU (EUVD) identifier?

Yes. CVE-2019-25220 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2019-19368.

When was CVE-2019-25220 published?

CVE-2019-25220 was published on 2024-11-18 and last updated on 2026-06-17.

CVE-2019-25220

CVE-2019-25220 is a high-severity vulnerability in Bitcoin Bitcoin Core with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-770.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 1% (52nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2019-19368
Weakness: CWE-770
Affected product: Bitcoin Bitcoin Core
Published: 2024-11-18
Last modified: 2026-06-17

Description

Bitcoin Core before 24.0.1 allows remote attackers to cause a denial of service (daemon crash) via a flood of low-difficulty header chains (aka a "Chain Width Expansion" attack) because a node does not first verify that a presented chain has enough work before committing to store it.

Frequently asked questions

What is CVE-2019-25220?: Bitcoin Core before 24.0.1 allows remote attackers to cause a denial of service (daemon crash) via a flood of low-difficulty header chains (aka a "Chain Width Expansion" attack) because a node does not first verify that a presented chain has enough work before committing to store it.
How severe is CVE-2019-25220?: CVE-2019-25220 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2019-25220 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-25220?: CVE-2019-25220 affects Bitcoin Bitcoin Core. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2019-25220?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2019-25220 have an EU (EUVD) identifier?: Yes. CVE-2019-25220 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2019-19368.
When was CVE-2019-25220 published?: CVE-2019-25220 was published on 2024-11-18 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:bitcoin:bitcoin_core:*:*:*:*:*:*:*:*

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