ZeroBrew version 0.3.1 and prior Missing Checksum Verification RCE via shim.rb (CVE-2026-53970) | HOL Guard CVE

High · CVSS 7.5CVE-2026-53970

ZeroBrew version 0.3.1 and prior Missing Checksum Verification RCE via shim.rb

Answer in brief

CVE-2026-53970 records a High severity (CVSS 7.5) vulnerability in ZeroBrew version 0.3.1 and prior Missing Checksum Verification RCE via shim.rb. The current sources do not mark it as known exploited. The current feed maps lucasgelfond/ZeroBrew (generic), lucasgelfond/ZeroBrew (generic), lucasgelfond/ZeroBrew (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 14, 2026Updated Aug 18, 2026Source checked Sep 29, 2026First seen by HOL Aug 14, 2026Material review Aug 18, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.5
Exploitation: Not marked as known exploited
Affected software: 3 mapped packages or products
Fix availability: Not reported

Why this deserves its current priority

CVSS is 7.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps lucasgelfond/ZeroBrew (generic), lucasgelfond/ZeroBrew (generic), lucasgelfond/ZeroBrew (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
lucasgelfond/ZeroBrewgeneric	0	Not reported
lucasgelfond/ZeroBrewgeneric	>=0 <=0.3.1	Not reported
lucasgelfond/ZeroBrewgeneric	*	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for lucasgelfond/ZeroBrew, lucasgelfond/ZeroBrew, lucasgelfond/ZeroBrew.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Aug 14, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 18, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 14, 2026

Sources and claim methodology

Upstream source description

ZeroBrew version 0.3.1 and prior contains a missing integrity verification vulnerability in the Ruby compatibility shim that allows network attackers to execute arbitrary code by substituting malicious content at formula resource or URL-based patch URLs without checksum validation. Attackers can intercept or replace downloads for secondary resource and patch paths in shim.rb, injecting attacker-controlled build steps or source tree modifications that execute during source builds via 'zb install --build-from-source' without any integrity warning.

Quoted source text, attributed separately from HOL analysis.