apko is vulnerable to path traversal in apko dirFS which allows filesystem writes outside base
apko allows users to build and publish OCI container images built from apk packages. From version 0.14.8 to before 1.1.1, a path traversal vulnerability was discovered in apko's dirFS filesystem abstraction. An attacker who can supply a malicious APK package (e.g., via a compromised or typosquatted repository) could create directories or symlinks outside the intended installation root. The MkdirAll, Mkdir, and Symlink methods in pkg/apk/fs/rwosfs.go use filepath.Join() without validating that the resulting path stays within the base directory. This issue has been patched in version 1.1.1.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-25121
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 8 Nov 2026, 02:03 UTC · Revision 1
Source evidence
apko is vulnerable to path traversal in apko dirFS which allows filesystem writes outside base
core-osv · Original sourcePublished 4 Feb 2026, 19:02 UTC
apko allows users to build and publish OCI container images built from apk packages. From version 0.14.8 to before 1.1.1, a path traversal vulnerability was discovered in apko's dirFS filesystem abstraction. An attacker who can supply a malicious APK package (e.g., via a compromised or typosquatted repository) could create directories or symlinks outside the intended installation root. The MkdirAll, Mkdir, and Symlink methods in pkg/apk/fs/rwosfs.go use filepath.Join() without validating that the resulting path stays within the base directory. This issue has been patched in version 1.1.1.
osv:CVE-2026-25121
Complete source record
{
"id": "5647f0a5fb8ef51f79fce2011b7ed0c00571ed7b8351d0528a643da8927cebc4",
"url": "https://osv.dev/vulnerability/CVE-2026-25121",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "apko is vulnerable to path traversal in apko dirFS which allows filesystem writes outside base",
"summary": "apko allows users to build and publish OCI container images built from apk packages. From version 0.14.8 to before 1.1.1, a path traversal vulnerability was discovered in apko's dirFS filesystem abstraction. An attacker who can supply a malicious APK package (e.g., via a compromised or typosquatted repository) could create directories or symlinks outside the intended installation root. The MkdirAll, Mkdir, and Symlink methods in pkg/apk/fs/rwosfs.go use filepath.Join() without validating that the resulting path stays within the base directory. This issue has been patched in version 1.1.1.",
"evidence": "osv:CVE-2026-25121",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2026-25121",
"aliases": [
"CVE-2026-25121",
"GHSA-5g94-c2wx-8pxw",
"GO-2026-4405"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/chainguard-dev/apko",
"type": "GIT",
"events": [
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{
"fixed": "3286a0b290e05ddd57b864f0465bb93aa6ea2484"
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{
"fixed": "d8b7887a968a527791b3c591ae83928cb49a9f14"
}
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"database_specific": {
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{
"cpe": "cpe:2.3:a:chainguard:apko:*:*:*:*:*:go:*:*",
"range": [
{
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{
"fixed": "1.1.1"
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"source": "CPE_RANGE"
},
{
"range": [
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"source": "REFERENCES_COMMIT"
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"v0.16.0",
"v0.15.0",
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],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-25121.json"
}
}
],
"modified": "2026-10-28T02:30:52.941742189Z",
"provider": "osv",
"references": [
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/25xxx/CVE-2026-25121.json",
"https://github.com/chainguard-dev/apko/security/advisories/GHSA-5g94-c2wx-8pxw",
"https://nvd.nist.gov/vuln/detail/CVE-2026-25121",
"https://github.com/chainguard-dev/apko/commit/d8b7887a968a527791b3c591ae83928cb49a9f14"
],
"provider_metadata": {
"cwe_ids": [
"CWE-23"
],
"cna_assigner": "GitHub_M",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/25xxx/CVE-2026-25121.json"
}
},
"related_cves": [
{
"value": "CVE-2026-25121",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 521601,
"published_at": "2026-02-04T19:02:17.979+00:00"
}