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

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

5.5 · CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

EPSS

• CVE-2026-25122: 0.13% estimated exploitation activity in the next 30 days; percentile 2.51 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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, Released in v1.1.0. Acknowledgements apko thanks Oleh Konko from 1seal for discovering and reporting this issue.

Published by the source

3 Feb 2026, 23:58 UTC

Last modified by the source

23 Feb 2026, 22:19 UTC

Source last checked

26 Oct 2026, 15:14 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-6p9p-q6wh-9j89

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# Patch Next advisory brief: CVE-2026-25122

Advisory: apko affected by unbounded resource consumption in expandapk.Split on attacker-controlled .apk streams
IDs: CVE-2026-25122, GHSA-6p9p-q6wh-9j89
Record: https://patchnext.com/advisories/cve-2026-25122 (revision 1, source checked 26 Oct 2026, 15:14 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: chainguard.dev/apko 1.1.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go chainguard.dev/apko: affected >= 0.14.8, < 1.1.0; fixed in 1.1.0

## Suggested inspection (read-only)
- Go chainguard.dev/apko: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on chainguard.dev/apko.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-6p9p-q6wh-9j89 (GitHub-reviewed advisory GHSA-6p9p-q6wh-9j89 lists affected ranges: Go chainguard.dev/apko >=0.14.8 <1.1.0)

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