Security Digest · Vulnerability record
CVE-2026-2611: MLflow: Improper Origin Validation in MLflow Assistant /ajax-api Endpoints Enables Browser-Mediated Local Command Execution
In MLflow version 3.9.0, the MLflow Assistant feature introduced improper origin validation in its /ajax-api endpoints.
CVSS 9.6 Critical EPSS 0.4% · p35
Should you act?
Critical and remotely reachable
No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.
- Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.4%, percentile 35: FIRST’s model estimates a 0.4% chance of exploitation activity in the next 30 days, higher than 35% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Needs a user to click or open something. Phishing makes that realistic, but it is not wormable.
- Only applies if your dependency tree includes
mlflow(PyPI) = 3.9.0, fixed in 3.10.0. Check your lockfile, including transitive dependencies.
What it is
In MLflow version 3.9.0, the MLflow Assistant feature introduced improper origin validation in its /ajax-api endpoints. This vulnerability allows a remote attacker to exploit cross-origin requests from a malicious webpage to interact with the MLflow Assistant running on a victim's local machine. By bypassing the loopback-only restriction, the attacker can modify the Assistant's configuration to enable full access, which in turn allows the execution of arbitrary commands via the Claude Code sub-agent. This issue is resolved in version 3.10.0.
From the GitHub advisory
In MLflow version 3.9.0, the MLflow Assistant feature introduced improper origin validation in its /ajax-api endpoints. This vulnerability allows a remote attacker to exploit cross-origin requests from a malicious webpage to interact with the MLflow Assistant running on a victim's local machine. By bypassing the loopback-only restriction, the attacker can modify the Assistant's configuration to enable full access, which in turn allows the execution of arbitrary commands via the Claude Code sub-agent. This issue is resolved in version 3.10.0.
Weakness type: CWE-346, CWE-940.
Product: mlflow (PyPI) · Assigned by: @huntr_ai · Published: 2026-05-19
Affected and fixed versions
| Ecosystem | Package | Vulnerable | First fixed |
|---|---|---|---|
| PyPI | mlflow | = 3.9.0 | 3.10.0 |
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| mlflow | mlflow/mlflow | unspecified < 3.10.0 |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| @huntr_ai | 3.0 | 9.6 Critical | CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H |
| redhat-SADP | 3.1 | 9.6 Critical | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H |
| GitHub | 3.1 | 9.6 | CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H |
- Attack vector: network (remotely reachable)
- Attack complexity: low
- Privileges required: none (no login)
- User interaction: required (a user must click/open something)
- Scope: changed (can affect other components)
CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.
Exploitation and urgency
- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc, automatable no, technical impact total.
- FIRST EPSS (model of 2026-10-21): 0.41% probability of exploitation activity in the next 30 days; percentile 35.
Timeline
- — CVE record published by @huntr_ai
- — GitHub-reviewed advisory GHSA-67c5-x5mf-rppq published (critical)
- — CVE record last updated
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vulnerability records
- GitHub Advisory GHSA-67c5-x5mf-rppq github.com
- CVE.org record CVE-2026-2611 cve.org
- NVD entry CVE-2026-2611 nvd.nist.gov
Other references from the CVE record and advisory
- huntr.com huntr.com
- github.com github.com
- access.redhat.com access.redhat.com
- RHBZ#2479797 bugzilla.redhat.com
- security.access.redhat.com security.access.redhat.com
- github.com github.com
- github.com github.com
- pypi.org pypi.org