# CVE-2026-115886: MLflow: SSRF on unauthenticated MLflow servers via third-party scorer kwargs in the scorer invoke, register, and GenAI evaluate endpoints


- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 23 Oct 2026
- **Updated:** 29 Oct 2026
- **Also known as:** BIT-mlflow-2026-115886, GHSA-2wqp-q3c6-ccj5

## What is CVE-2026-115886?

CVE-2026-115886 is a medium-severity vulnerability in mlflow, published on 23 Oct 2026. 

### Official description

MLflow is an open source AI engineering platform for agents, large language models, and machine learning models. From 3.12.0rc0 until 3.17.0, the scorer invoke, register, and GenAI evaluate endpoints, including unauthenticated POST /ajax-api/3.0/mlflow/scorer/invoke, accept serialized third-party scorer data that Scorer.model_validate_json resolves using a module-path allowlist without constraining the selected class or its constructor arguments. When optional trulens and trulens-providers-litellm packages are installed, an attacker can select mlflow.genai.scorers.trulens, choose a model URI outside MLflow's native provider registry so execution uses the LiteLLM fallback, and supply api_base and api_key values that cause the server to send an outbound request to an attacker-chosen or internal host with attacker-controlled headers and body. The vulnerable deserialization occurs before a tracking-store lookup or job submission. This issue is fixed in version 3.17.0.

Weakness: CWE-918 (Server-Side Request Forgery), CWE-470 (Use of Externally-Controlled Input to Select Classes or Code)

## Which versions are affected by CVE-2026-115886?

3 open source packages ship an affected version, including mlflow.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `mlflow` | Bitnami | From 3.12.0 | 3.17.0 |
| `mlflow` | PyPI | From 3.12.0rc0 | 3.17.0 |
| `mlflow` | PyPI | From 3.12.0rc0 | 3.17.0 |

## How do I fix CVE-2026-115886?

Upgrade mlflow to 3.17.0 or later.

## Is CVE-2026-115886 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-115886 exists.

Public exploit code:

- MLflow <3.17.0 - Unauthenticated SSRF via Third-Party (TruLens) Scorer (nuclei): http/cves/2026/CVE-2026-115886.yaml

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-115886 and fix it if it is affected.

What it is: CVE-2026-115886 is a medium-severity vulnerability in mlflow, published on 23 Oct 2026. 
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-115886 exists.

Affected packages and fixed versions:
- mlflow (Bitnami): affected from 3.12.0; fixed in 3.17.0
- mlflow (PyPI): affected from 3.12.0rc0; fixed in 3.17.0
- mlflow (PyPI): affected from 3.12.0rc0; fixed in 3.17.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-115886/ (Markdown: https://insights.sbomify.com/CVE-2026-115886/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-115886
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-115886
- OSV: https://osv.dev/vulnerability/CVE-2026-115886

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-115886/
Summaries are generated and may contain mistakes; the official description above is the record.