act: actions/cache server allows malicious cache injection
act is a project which allows for local running of github actions. Prior to version 0.2.86, act's built in actions/cache server listens to connections on all interfaces and allows anyone who can connect to it including someone anywhere on the internet to create caches with arbitrary keys and retrieve all existing caches. If they can predict which cache keys will be used by local actions, they can create malicious caches containing whatever files they please most likely allowing arbitrary remote code execution within the docker container. This issue has been patched in version 0.2.86.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-34042
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 5 Nov 2026, 23:57 UTC · Revision 1
Source evidence
act: actions/cache server allows malicious cache injection
core-osv · Original sourcePublished 31 Mar 2026, 01:46 UTC
act is a project which allows for local running of github actions. Prior to version 0.2.86, act's built in actions/cache server listens to connections on all interfaces and allows anyone who can connect to it including someone anywhere on the internet to create caches with arbitrary keys and retrieve all existing caches. If they can predict which cache keys will be used by local actions, they can create malicious caches containing whatever files they please most likely allowing arbitrary remote code execution within the docker container. This issue has been patched in version 0.2.86.
osv:CVE-2026-34042
Complete source record
{
"id": "2abdabbf90492056473c68252810475d072ca2cd988fa77d67d51d00c478d418",
"url": "https://osv.dev/vulnerability/CVE-2026-34042",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "act: actions/cache server allows malicious cache injection",
"summary": "act is a project which allows for local running of github actions. Prior to version 0.2.86, act's built in actions/cache server listens to connections on all interfaces and allows anyone who can connect to it including someone anywhere on the internet to create caches with arbitrary keys and retrieve all existing caches. If they can predict which cache keys will be used by local actions, they can create malicious caches containing whatever files they please most likely allowing arbitrary remote code execution within the docker container. This issue has been patched in version 0.2.86.",
"evidence": "osv:CVE-2026-34042",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2026-34042",
"aliases": [
"CVE-2026-34042",
"GHSA-x34h-54cw-9825",
"GO-2026-4890"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/nektos/act",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "e71313c826e8636eac974ba709dd60e02eef41bd"
},
{
"fixed": "c28c27e141e8b54f9853de82f421ee09846751f7"
}
],
"database_specific": {
"extracted_events": [
{
"range": [
{
"introduced": "0"
},
{
"fixed": "0.2.86"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StringRangeExpression"
},
{
"range": [
{
"fixed": "c28c27e141e8b54f9853de82f421ee09846751f7"
}
],
"source": "REFERENCES_COMMIT"
},
{
"range": [
{
"fixed": "e71313c826e8636eac974ba709dd60e02eef41bd"
}
],
"source": "REFERENCES_TAG",
"original_tag": "v0.2.86"
}
]
}
}
],
"versions": [
"v0.2.85",
"v0.2.84",
"v0.2.83",
"v0.2.82",
"v0.2.81",
"v0.2.80",
"v0.2.79",
"v0.2.78",
"v0.2.77",
"v0.2.76",
"v0.2.75",
"v0.2.74",
"v0.2.73",
"v0.2.72",
"v0.2.71",
"v0.2.70",
"v0.2.69",
"v0.2.68",
"v0.2.67",
"v0.2.66",
"v0.2.65",
"v0.2.64",
"v0.2.63",
"v0.2.62",
"v0.2.61",
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"v0.2.57",
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"v0.2.55",
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"v0.2.50",
"v0.2.49",
"v0.2.48",
"v0.2.47",
"v0.2.46",
"v0.2.45",
"v0.2.44",
"v0.2.43",
"v0.2.42",
"v0.2.41",
"v0.2.40",
"v0.2.39",
"v0.2.38",
"v0.2.37",
"v0.2.36",
"v0.2.35",
"v0.2.34",
"v0.2.33",
"v0.2.32",
"v0.2.31",
"v0.2.30",
"v0.2.29",
"v0.2.28",
"v0.2.27",
"v0.2.26",
"v0.2.25",
"v0.2.24",
"v0.2.23",
"v0.2.22",
"v0.2.21",
"v0.2.20",
"v0.2.19",
"v0.2.18",
"v0.2.17",
"v0.2.16",
"v0.2.15",
"v0.2.14",
"v0.2.13",
"v0.2.12",
"v0.2.11",
"v0.2.10",
"v0.2.9",
"v0.2.8",
"v0.2.7",
"v0.2.6",
"v0.2.5",
"v0.2.4",
"v0.2.3",
"v0.2.2",
"v0.2.1",
"v0.2.0",
"v0.1.3",
"v0.1.2",
"v0.1.1",
"v0.1.0",
"v0.0.5",
"v0.0.4",
"v0.0.3",
"v0.0.2",
"v0.0.1"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-34042.json"
}
}
],
"modified": "2026-10-28T02:30:45.266019381Z",
"provider": "osv",
"references": [
"https://code.forgejo.org/forgejo/runner/issues/294",
"https://github.com/nektos/act/releases/tag/v0.2.86",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34042.json",
"https://github.com/nektos/act/security/advisories/GHSA-x34h-54cw-9825",
"https://nvd.nist.gov/vuln/detail/CVE-2026-34042",
"https://github.com/nektos/act/commit/c28c27e141e8b54f9853de82f421ee09846751f7"
],
"provider_metadata": {
"cwe_ids": [
"CWE-862"
],
"cna_assigner": "GitHub_M",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34042.json"
}
},
"related_cves": [
{
"value": "CVE-2026-34042",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 513271,
"published_at": "2026-03-31T01:46:15.747+00:00"
}