CVE-2026-29049: melange: unbounded HTTP download in `melange update-cache` can exhaust disk in CI

Severity: medium (CVSS 4.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-03-06 · updated 2026-07-07
Weakness: CWE-400

Description

melange allows users to build apk packages using declarative pipelines. In version 0.40.5 and prior, 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 runne. Version 0.43.4 contains a patch.

Affected products

chainguard-dev melange: through 0.40.5

References

https://github.com/chainguard-dev/melange/commit/652ca5af08588f78e2d405e64b058fac8398d23f
https://github.com/chainguard-dev/melange/pull/2379
https://github.com/chainguard-dev/melange/releases/tag/v0.43.4
https://github.com/chainguard-dev/melange/security/advisories/GHSA-7rp8-r62p-q6wc

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