CVE-2026-25122 | apko is vulnerable to unbounded resource consumption in expandapk.Split on attacker-controlled .apk streams

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.

Published: 2026-02-04 Last update: 2026-02-20 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-25122 is rated Low Risk (22.6/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.01%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-25122

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-02-05 0.01%

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-25122

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
1.8 3.6 [email protected]

Weakness enumeration for CVE-2026-25122

GitHub Security Advisory for CVE-2026-25122

GHSA-6p9p-q6wh-9j89 · Severity: medium · Ecosystem: go — apko affected by unbounded resource consumption in expandapk.Split on attacker-controlled .apk streams

Affected software / configurations for CVE-2026-25122

Vendor Product Version Raw CPE
chainguard apko >= 0.14.8, < 1.1.0 cpe:2.3:a:chainguard:apko:*:*:*:*:*:go:*:*

References for CVE-2026-25122

cvelogic Threat Intelligence