CVE-2026-0545 — mlflow
CRITICALCVE-2026-0545 is a critical-severity (CVSS 9.1) Missing Authentication vulnerability in mlflow. No vendor fix is recorded yet; mitigation options are listed below.
mlflow: FastAPI job endpoints under `/ajax-api/3.0/jobs/*` are not protected by authentication or authorization
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-0545.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2026-0545 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
mlflowReal-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
In mlflow/mlflow, the FastAPI job endpoints under /ajax-api/3.0/jobs/* are not protected by authentication or authorization when the basic-auth app is enabled. This vulnerability affects the latest version of the repository. If job execution is enabled (MLFLOW_SERVER_ENABLE_JOB_EXECUTION=true) and any job function is allowlisted, any network client can submit, read, search, and cancel jobs without credentials, bypassing basic-auth entirely. This can lead to unauthenticated remote code execution if allowed jobs perform privileged actions such as shell execution or filesystem changes. Even if jobs are deemed safe, this still constitutes an authentication bypass, potentially resulting in job spam, denial of service (DoS), or data exposure in job results.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | mlflow | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mlflow, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
No patched version of mlflow has shipped for CVE-2026-0545 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
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.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-0545 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-0545. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
How to detect CVE-2026-0545
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id cve-2026-0545 -u https://target- Template
- MLflow Job API - Authentication Bypass
- Severity
- critical
- Impact
- Unauthenticated attackers can execute jobs remotely, potentially leading to remote code execution, denial of service, or data exposure.
- Remediation
- Update to the latest version with fixed authentication enforcement on job endpoints.
Template by ProjectDiscovery nuclei-templates (DhiyaneshDk), MIT licensed. View the full template. Scan only systems you are authorised to test.
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.
This Important flaw in MLflow allows unauthenticated access to FastAPI job endpoints when `basic-auth` is enabled, bypassing security controls. A remote attacker could exploit this to achieve unauthenticated remote code execution if job execution is enabled and configured for privileged operations. This also poses…
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat OpenShift AI 3.4 | rhoai/odh-pipeline-runtime-datascience-cpu-py312-rhel9:1787073866 | RHSA-2026:60520 |
Frequently Asked Questions
Is CVE-2026-0545 in your dependencies?
O3 Security finds CVE-2026-0545 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.