apko affected by unbounded resource consumption in expandapk.Split on attacker-controlled .apk streams in chainguard.dev/apko

Open Source Vulnerabilities CVE-2026-25122

apko allows users to build and publish OCI container images built from apk packages. From version 0.14.8 to before 1.1.0, expandapk.Split drains the first gzip stream of an APK archive via io.Copy(io.Discard, gzi) without explicit bounds. With an attacker-controlled input stream, this can force large gzip inflation work and lead to resource exhaustion (availability impact). The Split function reads the first tar header, then drains the remainder of the gzip stream by reading from the gzip reader directly without any maximum uncompressed byte limit or inflate-ratio cap. A caller that parses attacker-controlled APK streams may be forced to spend excessive CPU time inflating gzip data, leading to timeouts or process slowdown. This issue has been patched in version 1.1.0.

Open Source Vulnerabilities GHSA-6p9p-q6wh-9j89

`expandapk.Split` drains the first gzip stream of an APK archive via `io.Copy(io.Discard, gzi)` without explicit bounds. With an attacker-controlled input stream, this can force large gzip inflation work and lead to resource exhaustion (availability impact). The `Split` function reads the first tar header, then drains the remainder of the gzip stream by reading from the gzip reader directly without any maximum uncompressed byte limit or inflate-ratio cap. A caller that parses attacker-controlled APK streams may be forced to spend excessive CPU time inflating gzip data, leading to timeouts or process slowdown. **Fix:** Fixed with [2be3903](https://github.com/chainguard-dev/apko/commit/2be3903fe194ad46351840f0569b35f5ac965f09), Released in v1.1.0. **Acknowledgements** apko thanks Oleh Konko from [1seal](https://1seal.org/) for discovering and reporting this issue.

Open Source Vulnerabilities GO-2026-4406

apko affected by unbounded resource consumption in expandapk.Split on attacker-controlled .apk streams in chainguard.dev/apko