CVE-2023-28118Network attack vector

Application crash via unrestricted YAML alias expansion

Published Mar 20, 2023 · Updated Feb 25, 2025

Denial of service in Charles Korn kaml before 0.53.0 allows remote attackers to crash applications via recursive YAML aliases. YamlNodeReader resolves aliases into stored YamlNode objects without restricting anchor and alias expansion, allowing nested references to consume excessive memory. The host application must parse attacker-controlled YAML containing anchors and aliases; the consequence is memory exhaustion and an application crash.

CVSS severity7.5
High
EPSS probability0.97%
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 Charles Korn kaml before 0.53.0 allows remote attackers to crash applications via recursive YAML aliases. YamlNodeReader resolves aliases into stored YamlNode objects without restricting anchor and alias expansion, allowing nested references to consume excessive memory. The host application must parse attacker-controlled YAML containing anchors and aliases; the consequence is memory exhaustion and an application crash.

The record

CVE
CVE-2023-28118
Published
Mar 20, 2023
Updated
Feb 25, 2025
Vendor
Charles Korn
Product
kaml
Classifications
CWE-776, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 20, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 25, 2025Record 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=< 0.53.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Charles Korn · kamlversion=< 0.53.0

Published CVSS scores

7.5GitHubCVSS: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 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-776Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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