CVE-2024-55875Public exploitNetwork attack vector

Denial of service via internal entity expansion

Published Dec 12, 2024 · Updated Jun 9, 2026

Denial of service in http4k-format-xml before 6.50.0.0 allows remote attackers to exhaust server resources with crafted XML. The defaultXmlParsingConfig used by Body.xml() and Document.asXmlDocument() accepts DOCTYPE declarations, permitting recursive internal entities to expand during parsing. An application must pass untrusted XML to either parser path; successful exploitation consumes JVM resources and interrupts the service.

CVSS severity9.8
Critical
EPSS probability1.92%
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 http4k-format-xml before 6.50.0.0 allows remote attackers to exhaust server resources with crafted XML. The defaultXmlParsingConfig used by Body.xml() and Document.asXmlDocument() accepts DOCTYPE declarations, permitting recursive internal entities to expand during parsing. An application must pass untrusted XML to either parser path; successful exploitation consumes JVM resources and interrupts the service.

The record

CVE
CVE-2024-55875
Published
Dec 12, 2024
Updated
Jun 9, 2026
Vendor
http4k Ltd
Product
http4k
Classifications
CWE-918, CWE-200, CWE-611, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 12, 2024CVE publishedPublication date reported by the CVE source.
  2. Jun 9, 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=< 6.50.0.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

http4k Ltd · http4kversion=< 6.50.0.0

Published CVSS scores

9.8GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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 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 exploitPublished

Weakness, pattern, technique

CWE-918Server-Side Request Forgery (SSRF)
CWE-200Exposure of Sensitive Information to an Unauthorized Actor
CWE-611Improper Restriction of XML External Entity Reference
T1499.004Application or System Exploitation

Public exploit references

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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