PYSEC-2026-3658
Vulnerability from pysec - Published: 2026-08-19 11:56 - Updated: 2026-08-19 12:16Through version 1.3.0, the jailexec connection plugin's put_file resolved a transfer's destination to a path on the jail host ( + ) and ran mkdir -p and mv there as root on the host. Those commands follow symbolic links, and the path was operated on outside the jail, so a symlink existing inside the jail was followed by the host-side, root-privileged mv.
A party controlling content inside a managed jail (the jail's root, or any process able to create a symlink in a directory an Ansible task later writes to) can therefore cause an arbitrary root-owned write on the host, outside the jail — a full jail escape. Arbitrary root-owned host writes are readily escalated to host compromise (e.g. cron, rc.d, authorized_keys).
Preconditions: the operator runs a copy/template/fetch-style task (anything using put_file) against the jail, and the attacker can place a symlink inside the jail at or above the task's destination before the transfer runs.
Patches: Fixed in 2.0.0. File transfers now run inside the jail via jexec (mkdir -p && cat > for put_file; cat < for fetch_file), so every path resolves within the jail's chroot. An in-jail symlink can at most redirect within the same jail and can no longer reach the host.
Workarounds: None in affected versions; upgrade to 2.0.0.
| Name | purl | ansible-jailexec | pkg:pypi/ansible-jailexec |
|---|
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "ansible-jailexec",
"purl": "pkg:pypi/ansible-jailexec"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "2.0.0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"1.2.0",
"1.3.0"
]
}
],
"aliases": [
"CVE-2026-55074",
"GHSA-cxgv-hp74-jj7r"
],
"details": "Through version 1.3.0, the jailexec connection plugin\u0027s put_file resolved a transfer\u0027s destination to a path on the jail host (\u003cjail filesystem root\u003e + \u003cdestination\u003e) and ran mkdir -p and mv there as root on the host. Those commands follow symbolic links, and the path was operated on outside the jail, so a symlink existing inside the jail was followed by the host-side, root-privileged mv.\n\nA party controlling content inside a managed jail (the jail\u0027s root, or any process able to create a symlink in a directory an Ansible task later writes to) can therefore cause an arbitrary root-owned write on the host, outside the jail \u2014 a full jail escape. Arbitrary root-owned host writes are readily escalated to host compromise (e.g. cron, rc.d, authorized_keys).\n\nPreconditions: the operator runs a copy/template/fetch-style task (anything using put_file) against the jail, and the attacker can place a symlink inside the jail at or above the task\u0027s destination before the transfer runs.\n\nPatches: Fixed in 2.0.0. File transfers now run inside the jail via jexec (mkdir -p \u003cdir\u003e \u0026\u0026 cat \u003e \u003cdest\u003e for put_file; cat \u003c \u003csrc\u003e for fetch_file), so every path resolves within the jail\u0027s chroot. An in-jail symlink can at most redirect within the same jail and can no longer reach the host.\n\nWorkarounds: None in affected versions; upgrade to 2.0.0.",
"id": "PYSEC-2026-3658",
"modified": "2026-08-19T12:16:19.586215Z",
"published": "2026-08-19T11:56:26.241512Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/chofstede/ansible_jailexec/security/advisories/GHSA-cxgv-hp74-jj7r"
},
{
"type": "WEB",
"url": "https://github.com/chofstede/ansible_jailexec/commit/6e80eecb2db7aebd1258fded6ae5c3aba1dd4123"
},
{
"type": "PACKAGE",
"url": "https://github.com/chofstede/ansible_jailexec"
},
{
"type": "PACKAGE",
"url": "https://pypi.org/project/ansible-jailexec"
},
{
"type": "ADVISORY",
"url": "https://github.com/advisories/GHSA-cxgv-hp74-jj7r"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-55074"
}
],
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "Ansible FreeBSD Jail Connection Plugin: Jail escape via symlink following in put_file (host-side root mv)"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.