CVE-2026-42575Network attack vector

Arbitrary package injection via unchecked APKINDEX checksum

Published May 9, 2026 · Updated May 9, 2026

Integrity verification failure in Chainguard apko before 1.2.7 allows remote attackers to place arbitrary packages in built images. The getPackageImpl() path computes the downloaded package control hash but never compares it with ChecksumString() from the signed APKINDEX. Exploitation requires control of download responses through a compromised mirror, an HTTP repository, or a poisoned CDN cache, and results in attacker-chosen content in produced OCI images.

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

What happened

Integrity verification failure in Chainguard apko before 1.2.7 allows remote attackers to place arbitrary packages in built images. The getPackageImpl() path computes the downloaded package control hash but never compares it with ChecksumString() from the signed APKINDEX. Exploitation requires control of download responses through a compromised mirror, an HTTP repository, or a poisoned CDN cache, and results in attacker-chosen content in produced OCI images.

The record

CVE
CVE-2026-42575
Published
May 9, 2026
Updated
May 9, 2026
Vendor
Chainguard
Product
apko
Classifications
CWE-345, CWE-494, T1195.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 9, 2026CVE publishedPublication date reported by the CVE source.
  2. May 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=< 1.2.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Chainguard · apkoversion=< 1.2.7

Published CVSS scores

7.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-345Insufficient Verification of Data Authenticity
CWE-494Download of Code Without Integrity Check
T1195.001Compromise Software Dependencies and Development Tools

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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