How severe is CVE-2018-16859?

CVE-2018-16859 has a CVSS score of 4.4/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2018-16859?

CVE-2018-16859 affects the following packages: ansible (PyPI), ansible (PyPI), ansible (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2018-16859?

Update ansible to 2.7.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2018-16859 is resolved across your whole dependency graph.

How do I detect CVE-2018-16859 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ansible, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2018-16859 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2018-16859 actively exploited in the wild?

No public exploit code has been indexed for CVE-2018-16859 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2018-16859?

CVE-2018-16859 has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 46th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2018-16859?

CVE-2018-16859 is classified as CWE-532 (CWE-532). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2018-16859 published, and has it been updated?

CVE-2018-16859 was published on November 29, 2018 and was last updated on October 20, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍

🐍 PyPI

Not in CISA KEV

MEDIUM severity

CVE-2018-16859 — ansible

MEDIUMFix: ansible/ansible#49142

CVE-2018-16859 is a medium-severity (CVSS 4.4) CWE-532 vulnerability in ansible. A fix is available for ansible — see the affected versions and patch details below.

Ansible Logs Passwords If PowerShell ScriptBlock is Enabled

Also known asGHSA-v735-2pp6-h86rPYSEC-2018-60

Published

Nov 29, 2018

Updated

Oct 20, 2026

Affected

3 pkgs

Patched

3 / 3

Exploits

None indexed

Exploitation data as of Nov 5, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs46th percentile — riskier than 46% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

3 pkgs affected

🐍ansible🐍ansible🐍ansible

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

Execution of Ansible playbooks on Windows platforms with PowerShell ScriptBlock logging and Module logging enabled can allow for 'become' passwords to appear in EventLogs in plaintext. A local user with administrator privileges on the machine can view these logs and discover the plaintext password. Ansible Engine 2.8 and older are believed to be vulnerable.

Affected Packages

3 total 3 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`ansible`	≥ 2.7.0a1&&< 2.7.3	2.7.3`pip install --upgrade 'ansible==2.7.3'`
🐍PyPI	`ansible`	all versions	2.5.12`pip install --upgrade 'ansible==2.5.12'`
🐍PyPI	`ansible`	≥ 2.6.0a1&&< 2.6.9	2.6.9`pip install --upgrade 'ansible==2.6.9'`

Affected Products

1 product · 4 configurations

Application

ansible engineredhat

≥ 2.7.5 && ≤ 2.8

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ansible, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update ansible to 2.7.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2018-16859 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate

CloudForms and Satellite 6 are not affected by this issue, since Microsoft Windows is not a supported platform.

Product	Fixed in	Advisory
Red Hat Ansible Engine 2.5 for RHEL 7	`ansible-0:2.5.13-1.el7ae`	RHSA-2018:3770
Red Hat Ansible Engine 2.6 for RHEL 7	`ansible-0:2.6.10-1.el7ae`	RHSA-2018:3771
Red Hat Ansible Engine 2.7 for RHEL 7	`ansible-0:2.7.4-1.el7ae`	RHSA-2018:3773
Red Hat Ansible Engine 2 for RHEL 7	`ansible-0:2.7.4-1.el7ae`	RHSA-2018:3772

Frequently Asked Questions

O3 Security · Impact-Aware SCA

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