CVE-2026-29049Network attack vector

Build-runner disk exhaustion via unbounded download

Published Mar 6, 2026 · Updated Mar 6, 2026

Uncontrolled resource consumption in Chainguard melange before 0.43.4 allows remote attackers to exhaust build-runner disk space. The update-cache path in pkg/renovate/cache/cache.go passes a configuration-supplied URI response to io.Copy without a size bound or HTTP client timeout. Exploitation requires a build operator or CI workflow to process an attacker-influenced melange configuration, and the resulting unbounded write can interrupt the build runner.

CVSS severity4.3
Medium
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uncontrolled resource consumption in Chainguard melange before 0.43.4 allows remote attackers to exhaust build-runner disk space. The update-cache path in pkg/renovate/cache/cache.go passes a configuration-supplied URI response to io.Copy without a size bound or HTTP client timeout. Exploitation requires a build operator or CI workflow to process an attacker-influenced melange configuration, and the resulting unbounded write can interrupt the build runner.

The record

CVE
CVE-2026-29049
Published
Mar 6, 2026
Updated
Mar 6, 2026
Vendor
Chainguard
Product
Melange
Classifications
CWE-400, CWE-918, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 6, 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=<= 0.40.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Chainguard · Melangeversion=<= 0.40.5

Published CVSS scores

4.3GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L

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-400Uncontrolled Resource Consumption
CWE-918Server-Side Request Forgery (SSRF)
T1499Endpoint Denial of Service

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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