VULNpocalypse

CVE-2026-53995: MLflow 3.17.1 and prior Path Traversal via Trace ID API

Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.

Generated by VEDAS. Scores as of 2026-11-01 19:19 UTC. Rebuilt every few hours from cve-scores, CISA KEV and vedas-signatures. How this works and its limits.

What it is

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.

Description quoted from the CVE record (assigned by VulnCheck, published 2026-10-19).

Weakness: Improper Limitation of a Pathname to a Restricted Directory (‘Path Traversal’)

How it can be exploited

Exploitable over the network with low attack complexity with no special attack requirements needing no privileges and no user interaction. Impact: confidentiality none, integrity high, availability low. 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

CISA assessment (SSVC): CISA assesses that a public proof of concept exists. Automatable: yes. Technical impact: partial.

Public exploit evidence (Exploit Observer)

Also known as: EUVD-2026-104633, GHSA-wqmh-qccw-pqwf

VEDAS cluster: VEDAS:DOVEDEXTER

Exploit Observer links 6 pieces of public exploit code or detection modules that name this CVE or one of its aliases.

Exploit code and modules (6)

Code that names this CVE. A repository can be a working exploit, a scanner, a fake or malware; read it before running anything.

Vulnerability databases and vendor advisories (5)

Catalogue entries, not exploit evidence.

3 more references returned by Exploit Observer did not name this CVE or an alias, so they are left out.

VEDAS data as of 2026-11-01T17:12 UTC; fetched 2026-11-02.

Live scores

EPSS
0.006
low predicted chance of attack
VEDAS
0.989
strong exploit evidence
On CISA KEV
Not listed
Detection rule
Nuclei · Suricata

Who is affected

ProductAffectedNot affected
mlflow mlflowup to and including 3.17.1Not stated

Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.

Exploit Observer also maps it to: pypi mlflow.

How to fix it

No fixed version or vendor advisory is listed in the CVE record yet. Watch the vendor’s security page.

How to detect it

Nuclei template (active check)

MLflow - Unauthenticated Trace ID Path Traversal

MLflow 3.17.1 and earlier contains a path traversal vulnerability in the FileStore tracking backend. An unauthenticated attacker can submit a crafted trace ID containing traversal sequences to the POST /api/3.0/mlflow/traces endpoint, causing 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.

Name and description quoted from the template, written by VEDAS.

The template sends 1 request (POST /api/3.0/mlflow/traces); it decides using dsl matchers. Severity in the template: high. Marked as not yet verified against a live vulnerable target.

Run it against a host you own or are authorised to test:

bash
nuclei -u https://your-host -t CVE-2026-53995.yaml
Show the template (41 lines)
yaml
id: CVE-2026-53995

info:
  name: "MLflow - Unauthenticated Trace ID Path Traversal"
  author: vedas-arpsyndicate
  severity: high
  description: |
    MLflow 3.17.1 and earlier contains a path traversal vulnerability in the FileStore tracking
    backend. An unauthenticated attacker can submit a crafted trace ID containing traversal sequences
    to the POST /api/3.0/mlflow/traces endpoint, causing 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.
  reference:
    - https://www.exploit.observer/?keyword=CVE-2026-53995&match=exact
    - https://subdomain.center/?engine=ammonites&keyword=mlflow&match=exact
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L
    cvss-score: 8.2
    cve-id: CVE-2026-53995
    cwe-id: CWE-22
  metadata:
    verified: false
    max-request: 1
  tags: cve,cve2026,mlflow,lfi,traversal

http:
  - raw:
      - |
        POST /api/3.0/mlflow/traces HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/json

        {"trace":{"trace_info":{"trace_id":"../vedaspoc","trace_location":{"type":"MLFLOW_EXPERIMENT","mlflow_experiment":{"experiment_id":"0"}},"request_time":"1700000000000","state":"OK","trace_metadata":{},"tags":{}}}}

    matchers:
      - type: dsl
        dsl:
          - 'contains(body, "../vedaspoc")'
          - '!contains(body, "INVALID_PARAMETER_VALUE")'
          - 'status_code == 200'
        condition: and

CVE-2026-53995.yaml on GitHub

Suricata rules (network detection)

1 rule that alert on traffic matching this exploit: VEDAS CVE-2026-53995 MLflow - Unauthenticated Trace ID Path Traversal. Add them to your Suricata rule set and reload.

Show the rules
suricata
alert http $EXTERNAL_NET any -> $HTTP_SERVERS $HTTP_PORTS (msg:"VEDAS CVE-2026-53995 MLflow - Unauthenticated Trace ID Path Traversal"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"/mlflow/traces"; nocase; fast_pattern; http.request_body; content:"trace_id"; nocase; pcre:"/\x22trace_id\x22\s*:\s*\x22[^\x22]*\x2e\x2e[\x2f\x5c]/i"; classtype:web-application-attack; reference:cve,CVE-2026-53995; reference:url,https://www.exploit.observer/?keyword=CVE-2026-53995&match=exact; reference:url,https://subdomain.center/?engine=ammonites&keyword=mlflow&match=exact; sid:1093001; rev:1;)

CVE-2026-53995.rules on GitHub

References

Exploits and technical analysis

Other databases

Where this comes from

This advisory is generated automatically by VEDAS from: CVE.org record, cve-scores (EPSS and VEDAS), Exploit Observer, vedas-signatures. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.