CVE-2025-55198Network attack vector

CLI crash via malformed YAML type handling

Published Aug 13, 2025 · Updated Aug 14, 2025

Input-type validation flaws in Helm before 3.18.5 allow remote attackers to crash the CLI through malformed Chart.yaml or index.yaml files. The affected paths dereference a nil maintainer, assert dependency import-values as strings, or retain a nil chart-version entry instead of rejecting malformed YAML. Exploitation requires a user to lint the crafted chart or interact with the malicious repository, and the bounded result is termination of that Helm process.

CVSS severity6.5
Medium
EPSS probability0.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Input-type validation flaws in Helm before 3.18.5 allow remote attackers to crash the CLI through malformed Chart.yaml or index.yaml files. The affected paths dereference a nil maintainer, assert dependency import-values as strings, or retain a nil chart-version entry instead of rejecting malformed YAML. Exploitation requires a user to lint the crafted chart or interact with the malicious repository, and the bounded result is termination of that Helm process.

The record

CVE
CVE-2025-55198
Published
Aug 13, 2025
Updated
Aug 14, 2025
Vendor
The Helm Project
Product
Helm
Classifications
CWE-1287, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 13, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 14, 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=< 3.18.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Helm Project · Helmversion=< 3.18.5

Published CVSS scores

6.5GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:R/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-1287Improper Validation of Specified Type of Input
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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