# CVE-2026-53995 — mlflow

> As of 2026-10-20, CVE-2026-53995 is a HIGH-severity vulnerability in mlflow, CVSS v3.1 8.2, EPSS 0.5% (45.5th percentile). No Threadlinqs-tracked threat campaign has been attributed to CVE-2026-53995 as of 2026-10-20; the identifier is re-checked against the Threadlinqs threat corpus on every daily ingest.

**Last updated:** 2026-10-20

## What is CVE-2026-53995?

MLflow 3.17.1 and earlier contains a path traversal vulnerability in the FileStore tracking backend that allows unauthenticated attackers to control filesystem paths by submitting a crafted trace ID containing traversal sequences to the POST /api/3.0/mlflow/traces endpoint. Attackers can exploit FileStore.start_trace() to write trace_info.yaml, request_metadata, and tag files with attacker-controlled metadata outside the intended experiment trace directory, subject to the server process's filesystem permissions. FileStore is the default tracking backend before MLflow 3.7.0 and opt-in thereafter (the default changed to a SQLite database), so deployments in the earlier part of the affected range are vulnerable without special configuration while later ones are affected only when FileStore is explicitly selected.

The record classifies CVE-2026-53995 under weakness class [CWE-22](https://intel.threadlinqs.com/cwe/CWE-22). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on integrity. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 9 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 8.2 — HIGH (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L`)
- **CVSS v4.0 base score:** 8.8 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N`)
- **EPSS (FIRST):** 0.5% probability of exploitation in the next 30 days, higher than 45.5% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 7.9/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-10-19, last modified 2026-10-20

## Is CVE-2026-53995 being exploited?

Weaponised exploit code for CVE-2026-53995 is publicly available. 1 public proof-of-concept repository is tracked for this identifier. It currently carries a trending score of 49 in the Threadlinqs vulnerability feed.

- [SaiTeja-Erukude/CVE-2026-53995-mlflow-path-traversal](https://github.com/SaiTeja-Erukude/CVE-2026-53995-mlflow-path-traversal) (github)

## Affected products and versions

- [mlflow](https://intel.threadlinqs.com/vendors/mlflow): mlflow

## How to fix CVE-2026-53995

No vendor patch reference has been recorded for CVE-2026-53995 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-53995

No threat campaign in the Threadlinqs corpus currently references CVE-2026-53995, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.

## Sources

Enriched from CVE.org, NVD, public proof-of-concept repositories, FIRST EPSS. Last verified by Threadlinqs on 2026-10-21. This product uses the NVD API but is not endorsed or certified by the NVD.

**Exploit and proof of concept**

- [github.com — technical description](https://github.com/SaiTeja-Erukude/CVE-2026-53995-mlflow-path-traversal)

**Third-party advisory**

- [vulncheck.com — third party advisory](https://www.vulncheck.com/advisories/mlflow-path-traversal-via-trace-id-api)

**Issue tracking and product pages**

- [github.com — issue tracking](https://github.com/mlflow/mlflow/pull/26842)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-53995
Full detection coverage and IOCs for threats exploiting CVE-2026-53995 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp