CVE-2026-4035 (GCVE-0-2026-4035)

Vulnerability from cvelistv5 – Published: 2026-06-03 07:18 – Updated: 2026-06-03 13:10
VLAI
Title
Environment Variable Resolution Vulnerability in mlflow/mlflow
Summary
A vulnerability in mlflow/mlflow versions prior to 3.11.0 allows for the resolution of environment variables in AI Gateway secrets, which can be exploited to exfiltrate sensitive server-side environment credentials to an attacker-controlled endpoint. This issue arises because the `api_key` field in gateway secrets can accept `$ENV_VAR` references, which are resolved against the MLflow server's environment during runtime. The resolved secrets are then sent in provider authentication headers to the configured upstream `api_base`. This vulnerability can be exploited by low-privileged authenticated users in basic-auth deployments or by unauthenticated users in default deployments without `basic-auth`. The impact includes potential leakage of sensitive credentials such as cloud artifact credentials (`AWS_ACCESS_KEY_ID`, `AWS_SECRET_ACCESS_KEY`), which could lead to artifact poisoning and cross-boundary code execution in downstream environments. The issue is fixed in version 3.11.0.
Severity
9.1 (Critical)
CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L
SSVC
Exploitation: poc Automatable: no Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
  • CWE-201 - Insertion of Sensitive Information Into Sent Data
Assigner
References
Impacted products
Vendor Product Version
mlflow mlflow/mlflow Affected: unspecified , < 3.11.0 (custom)
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-4035",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-03T13:10:20.303201Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-06-03T13:10:24.407Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://huntr.com/bounties/f8e591a0-0f19-4910-b82e-16c9956f2233"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "mlflow/mlflow",
          "vendor": "mlflow",
          "versions": [
            {
              "lessThan": "3.11.0",
              "status": "affected",
              "version": "unspecified",
              "versionType": "custom"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "A vulnerability in mlflow/mlflow versions prior to 3.11.0 allows for the resolution of environment variables in AI Gateway secrets, which can be exploited to exfiltrate sensitive server-side environment credentials to an attacker-controlled endpoint. This issue arises because the `api_key` field in gateway secrets can accept `$ENV_VAR` references, which are resolved against the MLflow server\u0027s environment during runtime. The resolved secrets are then sent in provider authentication headers to the configured upstream `api_base`. This vulnerability can be exploited by low-privileged authenticated users in basic-auth deployments or by unauthenticated users in default deployments without `basic-auth`. The impact includes potential leakage of sensitive credentials such as cloud artifact credentials (`AWS_ACCESS_KEY_ID`, `AWS_SECRET_ACCESS_KEY`), which could lead to artifact poisoning and cross-boundary code execution in downstream environments. The issue is fixed in version 3.11.0."
        }
      ],
      "metrics": [
        {
          "cvssV3_0": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 9.1,
            "baseSeverity": "CRITICAL",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "LOW",
            "privilegesRequired": "LOW",
            "scope": "CHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L",
            "version": "3.0"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-201",
              "description": "CWE-201 Insertion of Sensitive Information Into Sent Data",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-03T07:18:08.512Z",
        "orgId": "c09c270a-b464-47c1-9133-acb35b22c19a",
        "shortName": "@huntr_ai"
      },
      "references": [
        {
          "url": "https://huntr.com/bounties/f8e591a0-0f19-4910-b82e-16c9956f2233"
        },
        {
          "url": "https://github.com/mlflow/mlflow/commit/4a3f2f720cb4f058c9e0c5b883e0acc9ab64a7f3"
        }
      ],
      "source": {
        "advisory": "f8e591a0-0f19-4910-b82e-16c9956f2233",
        "discovery": "EXTERNAL"
      },
      "title": "Environment Variable Resolution Vulnerability in mlflow/mlflow"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "c09c270a-b464-47c1-9133-acb35b22c19a",
    "assignerShortName": "@huntr_ai",
    "cveId": "CVE-2026-4035",
    "datePublished": "2026-06-03T07:18:08.512Z",
    "dateReserved": "2026-03-12T02:17:42.523Z",
    "dateUpdated": "2026-06-03T13:10:24.407Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-4035",
      "date": "2026-06-03",
      "epss": "0.00278",
      "percentile": "0.51428"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-4035\",\"sourceIdentifier\":\"security@huntr.dev\",\"published\":\"2026-06-03T09:16:13.083\",\"lastModified\":\"2026-06-03T14:16:45.847\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"A vulnerability in mlflow/mlflow versions prior to 3.11.0 allows for the resolution of environment variables in AI Gateway secrets, which can be exploited to exfiltrate sensitive server-side environment credentials to an attacker-controlled endpoint. This issue arises because the `api_key` field in gateway secrets can accept `$ENV_VAR` references, which are resolved against the MLflow server\u0027s environment during runtime. The resolved secrets are then sent in provider authentication headers to the configured upstream `api_base`. This vulnerability can be exploited by low-privileged authenticated users in basic-auth deployments or by unauthenticated users in default deployments without `basic-auth`. The impact includes potential leakage of sensitive credentials such as cloud artifact credentials (`AWS_ACCESS_KEY_ID`, `AWS_SECRET_ACCESS_KEY`), which could lead to artifact poisoning and cross-boundary code execution in downstream environments. The issue is fixed in version 3.11.0.\"}],\"metrics\":{\"cvssMetricV30\":[{\"source\":\"security@huntr.dev\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.0\",\"vectorString\":\"CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L\",\"baseScore\":9.1,\"baseSeverity\":\"CRITICAL\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"CHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"LOW\",\"availabilityImpact\":\"LOW\"},\"exploitabilityScore\":3.1,\"impactScore\":5.3}]},\"weaknesses\":[{\"source\":\"security@huntr.dev\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-201\"}]}],\"references\":[{\"url\":\"https://github.com/mlflow/mlflow/commit/4a3f2f720cb4f058c9e0c5b883e0acc9ab64a7f3\",\"source\":\"security@huntr.dev\"},{\"url\":\"https://huntr.com/bounties/f8e591a0-0f19-4910-b82e-16c9956f2233\",\"source\":\"security@huntr.dev\"},{\"url\":\"https://huntr.com/bounties/f8e591a0-0f19-4910-b82e-16c9956f2233\",\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\"}]}}",
    "vulnrichment": {
      "containers": "{\"cna\": {\"title\": \"Environment Variable Resolution Vulnerability in mlflow/mlflow\", \"providerMetadata\": {\"orgId\": \"c09c270a-b464-47c1-9133-acb35b22c19a\", \"shortName\": \"@huntr_ai\", \"dateUpdated\": \"2026-06-03T07:18:08.512Z\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"A vulnerability in mlflow/mlflow versions prior to 3.11.0 allows for the resolution of environment variables in AI Gateway secrets, which can be exploited to exfiltrate sensitive server-side environment credentials to an attacker-controlled endpoint. This issue arises because the `api_key` field in gateway secrets can accept `$ENV_VAR` references, which are resolved against the MLflow server\u0027s environment during runtime. The resolved secrets are then sent in provider authentication headers to the configured upstream `api_base`. This vulnerability can be exploited by low-privileged authenticated users in basic-auth deployments or by unauthenticated users in default deployments without `basic-auth`. The impact includes potential leakage of sensitive credentials such as cloud artifact credentials (`AWS_ACCESS_KEY_ID`, `AWS_SECRET_ACCESS_KEY`), which could lead to artifact poisoning and cross-boundary code execution in downstream environments. The issue is fixed in version 3.11.0.\"}], \"affected\": [{\"vendor\": \"mlflow\", \"product\": \"mlflow/mlflow\", \"versions\": [{\"version\": \"unspecified\", \"lessThan\": \"3.11.0\", \"status\": \"affected\", \"versionType\": \"custom\"}]}], \"references\": [{\"url\": \"https://huntr.com/bounties/f8e591a0-0f19-4910-b82e-16c9956f2233\"}, {\"url\": \"https://github.com/mlflow/mlflow/commit/4a3f2f720cb4f058c9e0c5b883e0acc9ab64a7f3\"}], \"metrics\": [{\"cvssV3_0\": {\"version\": \"3.0\", \"attackComplexity\": \"LOW\", \"attackVector\": \"NETWORK\", \"availabilityImpact\": \"LOW\", \"confidentialityImpact\": \"HIGH\", \"integrityImpact\": \"LOW\", \"privilegesRequired\": \"LOW\", \"scope\": \"CHANGED\", \"userInteraction\": \"NONE\", \"vectorString\": \"CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L\", \"baseScore\": 9.1, \"baseSeverity\": \"CRITICAL\"}}], \"problemTypes\": [{\"descriptions\": [{\"type\": \"CWE\", \"lang\": \"en\", \"description\": \"CWE-201 Insertion of Sensitive Information Into Sent Data\", \"cweId\": \"CWE-201\"}]}], \"source\": {\"advisory\": \"f8e591a0-0f19-4910-b82e-16c9956f2233\", \"discovery\": \"EXTERNAL\"}}, \"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-4035\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"poc\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-06-03T13:10:20.303201Z\"}}}], \"references\": [{\"url\": \"https://huntr.com/bounties/f8e591a0-0f19-4910-b82e-16c9956f2233\", \"tags\": [\"exploit\"]}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-06-03T13:09:52.628Z\"}}]}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-4035\", \"assignerOrgId\": \"c09c270a-b464-47c1-9133-acb35b22c19a\", \"state\": \"PUBLISHED\", \"assignerShortName\": \"@huntr_ai\", \"dateReserved\": \"2026-03-12T02:17:42.523Z\", \"datePublished\": \"2026-06-03T07:18:08.512Z\", \"dateUpdated\": \"2026-06-03T13:10:24.407Z\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.