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`melange update-cache` has unbounded HTTP download that can exhaust disk in CI

Moderate severity GitHub Reviewed Published Mar 2, 2026 in chainguard-dev/melange • Updated Mar 6, 2026

Package

gomod chainguard.dev/melange (Go)

Affected versions

<= 0.40.5

Patched versions

None

Description

melange update-cache downloads URIs from build configs via io.Copy without any size limit or HTTP client timeout (pkg/renovate/cache/cache.go). An attacker-controlled URI in a melange config can cause unbounded disk writes, exhausting disk on the build runner. Affected versions <= 0.40.5.

Fix: Merged
Acknowledgements

melange thanks Oleh Konko from 1seal for discovering and reporting this issue.

References

@antitree antitree published to chainguard-dev/melange Mar 2, 2026
Published to the GitHub Advisory Database Mar 2, 2026
Reviewed Mar 2, 2026
Published by the National Vulnerability Database Mar 6, 2026
Last updated Mar 6, 2026

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(12th percentile)

Weaknesses

Uncontrolled Resource Consumption

The product does not properly control the allocation and maintenance of a limited resource. Learn more on MITRE.

Server-Side Request Forgery (SSRF)

The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. Learn more on MITRE.

CVE ID

CVE-2026-29049

GHSA ID

GHSA-7rp8-r62p-q6wc

Source code

Credits

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