CVE-2026-53970Network attack vector

Code execution via unchecked source-build downloads

Published Aug 14, 2026 · Updated Aug 14, 2026

Missing integrity verification in ZeroBrew 0.3.1 and earlier allows remote attackers to execute code through source-build downloads. The Ruby compatibility shim fetches formula resources and URL-based patches with curl, then extracts or applies them without comparing their declared SHA-256 values. Exploitation requires a source build and control of, or a network position permitting substitution at, a referenced URL; injected build steps execute with the invoking user's privileges.

CVSS severity7.5
High
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Missing integrity verification in ZeroBrew 0.3.1 and earlier allows remote attackers to execute code through source-build downloads. The Ruby compatibility shim fetches formula resources and URL-based patches with curl, then extracts or applies them without comparing their declared SHA-256 values. Exploitation requires a source build and control of, or a network position permitting substitution at, a referenced URL; injected build steps execute with the invoking user's privileges.

The record

CVE
CVE-2026-53970
Published
Aug 14, 2026
Updated
Aug 14, 2026
Vendor
Lucas Gelfond
Product
ZeroBrew
Classifications
CWE-494, T1195.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 14, 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?

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  1. Affected versionversion=0 <=0.3.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Lucas Gelfond · ZeroBrewversion=0 <=0.3.1

Published CVSS scores

7.5VulnCheckCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
7.5VulnCheckCVSS:3.1/AV:N/AC:H/PR:N/UI:R/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 exploitUnconfirmed

Weakness, pattern, technique

CWE-494Download of Code Without Integrity Check
T1195.002Compromise Software Supply Chain

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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