CVE-2026-25122
apko affected by unbounded resource consumption in expandapk.Split on attacker-controlled .apk streams
Impact
`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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| go | chainguard.dev/apko | >= 0.14.8, < 1.1.0 | 1.1.0 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Chainguard | Apko | from 0.14.8 before 1.1.0 |