Vulnerability-Lookup

Vulnerability from bitnami_vulndb

Published

2026-06-05 05:40

Modified

2026-09-08 08:34

Summary

Apache Airflow: No certificate validation on SMTP STARTTLS connections

Details

Apache Airflow's EmailOperator and the underlying airflow.utils.email helpers established SMTP STARTTLS connections without verifying the remote certificate when the deployment used [email] smtp_starttls=True without [email] smtp_ssl. An attacker positioned between the worker and the configured SMTP server (network MITM — typical hostile-network attack-surface for environments where the SMTP relay sits outside the worker's trust boundary) could present a self-signed certificate, have the worker complete the STARTTLS handshake silently, and capture the SMTP AUTH credentials and message contents the worker forwarded.

This CVE covers the core apache-airflow side of the same root cause already covered for the SMTP provider by CVE-2026-41016 (published 2026-04-27, covering apache-airflow-providers-smtp). Users who already applied the SMTP-provider fix from CVE-2026-41016 should additionally upgrade apache-airflow to 3.2.2 or later to cover the core-side path through airflow.utils.email. Affects deployments configured with smtp_starttls=True and smtp_ssl=False where the SMTP relay is reachable across a less-trusted network segment than the worker.

Users are advised to upgrade to apache-airflow 3.2.2 or later.

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "Bitnami",
        "name": "airflow",
        "purl": "pkg:bitnami/airflow"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.0.0"
            },
            {
              "fixed": "3.2.2"
            }
          ],
          "type": "SEMVER"
        }
      ],
      "severity": [
        {
          "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
          "type": "CVSS_V3"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-49267"
  ],
  "database_specific": {
    "cpes": [
      "cpe:2.3:a:apache:airflow:*:*:*:*:*:python:*:*"
    ],
    "severity": "Medium"
  },
  "details": "Apache Airflow\u0027s EmailOperator and the underlying `airflow.utils.email` helpers established SMTP STARTTLS connections without verifying the remote certificate when the deployment used `[email] smtp_starttls=True` without `[email] smtp_ssl`. An attacker positioned between the worker and the configured SMTP server (network MITM \u2014 typical hostile-network attack-surface for environments where the SMTP relay sits outside the worker\u0027s trust boundary) could present a self-signed certificate, have the worker complete the STARTTLS handshake silently, and capture the SMTP AUTH credentials and message contents the worker forwarded.\n\nThis CVE covers the **core apache-airflow side** of the same root cause already covered for the SMTP provider by `CVE-2026-41016` (published 2026-04-27, covering `apache-airflow-providers-smtp`). Users who already applied the SMTP-provider fix from CVE-2026-41016 should additionally upgrade `apache-airflow` to 3.2.2 or later to cover the core-side path through `airflow.utils.email`. Affects deployments configured with `smtp_starttls=True` and `smtp_ssl=False` where the SMTP relay is reachable across a less-trusted network segment than the worker.\n\nUsers are advised to upgrade to `apache-airflow` 3.2.2 or later.",
  "id": "BIT-airflow-2026-49267",
  "modified": "2026-09-08T08:34:36.952Z",
  "published": "2026-06-05T05:40:51.158Z",
  "references": [
    {
      "type": "FIX",
      "url": "https://github.com/apache/airflow/pull/65346"
    },
    {
      "type": "ADVISORY",
      "url": "https://lists.apache.org/thread/6v2ds757000msmjmovnnqryqzks83ps0"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-49267"
    }
  ],
  "schema_version": "1.6.2",
  "summary": "Apache Airflow: No certificate validation on SMTP STARTTLS connections"
}

CVE-2026-49267 (GCVE-0-2026-49267)

Vulnerability from cvelistv5 – Published: 2026-06-01 07:53 – Updated: 2026-11-03 06:57

Title

Apache Airflow: No certificate validation on SMTP STARTTLS connections

Summary

Apache Airflow's EmailOperator and the underlying `airflow.utils.email` helpers established SMTP STARTTLS connections without verifying the remote certificate when the deployment used `[email] smtp_starttls=True` without `[email] smtp_ssl`. An attacker positioned between the worker and the configured SMTP server (network MITM — typical hostile-network attack-surface for environments where the SMTP relay sits outside the worker's trust boundary) could present a self-signed certificate, have the worker complete the STARTTLS handshake silently, and capture the SMTP AUTH credentials and message contents the worker forwarded. This CVE covers the **core apache-airflow side** of the same root cause already covered for the SMTP provider by `CVE-2026-41016` (published 2026-04-27, covering `apache-airflow-providers-smtp`). Users who already applied the SMTP-provider fix from CVE-2026-41016 should additionally upgrade `apache-airflow` to 3.2.2 or later to cover the core-side path through `airflow.utils.email`. Affects deployments configured with `smtp_starttls=True` and `smtp_ssl=False` where the SMTP relay is reachable across a less-trusted network segment than the worker. Users are advised to upgrade to `apache-airflow` 3.2.2 or later.

Severity

5.9 (Medium)


                        
                          CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-06-02 16:20 UTC

CWE

CWE-295 - Improper Certificate Validation

Assigner

apache CNA under the mitre root

CNA scorecard B 76/100 over 1265 records in the last 180 days details

References

2 references

URL	Tags
https://github.com/apache/airflow/pull/65346	patch
https://lists.apache.org/thread/6v2ds757000msmjmo…	vendor-advisory

Impacted products

2 products

Vendor	Product	Version
Apache Software Foundation	Apache Airflow	Affected: 2.0.0 , < 3.0.0 (semver)
Apache Software Foundation	Apache Airflow	Affected: 3.0.0 , < 3.2.2 (semver)

Credits

Francis Bergin (@francisbergin) Jarek Potiuk

Show details on NVD website

JSON

To clipboard

{
  "containers": {
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      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "HIGH",
              "attackVector": "NETWORK",
              "availabilityImpact": "NONE",
              "baseScore": 5.9,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "HIGH",
              "integrityImpact": "NONE",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-49267",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-02T16:20:50.236710Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-06-02T16:42:48.781Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://pypi.python.org",
          "defaultStatus": "unaffected",
          "packageName": "apache-airflow",
          "packageURL": "pkg:pypi/apache-airflow",
          "product": "Apache Airflow",
          "vendor": "Apache Software Foundation",
          "versions": [
            {
              "lessThan": "3.0.0",
              "status": "affected",
              "version": "2.0.0",
              "versionType": "semver"
            }
          ]
        },
        {
          "collectionURL": "https://pypi.python.org",
          "defaultStatus": "unaffected",
          "packageName": "apache-airflow-core",
          "packageURL": "pkg:pypi/apache-airflow-core",
          "product": "Apache Airflow",
          "vendor": "Apache Software Foundation",
          "versions": [
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              "lessThan": "3.2.2",
              "status": "affected",
              "version": "3.0.0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Francis Bergin (@francisbergin)"
        },
        {
          "lang": "en",
          "type": "remediation developer",
          "value": "Jarek Potiuk"
        }
      ],
      "descriptions": [
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          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "Apache Airflow\u0026#x27;s EmailOperator and the underlying `airflow.utils.email` helpers established SMTP STARTTLS connections without verifying the remote certificate when the deployment used `[email] smtp_starttls=True` without `[email] smtp_ssl`. An attacker positioned between the worker and the configured SMTP server (network MITM \u2014 typical hostile-network attack-surface for environments where the SMTP relay sits outside the worker\u0026#x27;s trust boundary) could present a self-signed certificate, have the worker complete the STARTTLS handshake silently, and capture the SMTP AUTH credentials and message contents the worker forwarded.\u003cbr\u003e\u003cbr\u003eThis CVE covers the **core apache-airflow side** of the same root cause already covered for the SMTP provider by `CVE-2026-41016` (published 2026-04-27, covering `apache-airflow-providers-smtp`). Users who already applied the SMTP-provider fix from CVE-2026-41016 should additionally upgrade `apache-airflow` to 3.2.2 or later to cover the core-side path through `airflow.utils.email`. Affects deployments configured with `smtp_starttls=True` and `smtp_ssl=False` where the SMTP relay is reachable across a less-trusted network segment than the worker.\u003cbr\u003e\u003cbr\u003eUsers are advised to upgrade to `apache-airflow` 3.2.2 or later."
            }
          ],
          "value": "Apache Airflow\u0027s EmailOperator and the underlying `airflow.utils.email` helpers established SMTP STARTTLS connections without verifying the remote certificate when the deployment used `[email] smtp_starttls=True` without `[email] smtp_ssl`. An attacker positioned between the worker and the configured SMTP server (network MITM \u2014 typical hostile-network attack-surface for environments where the SMTP relay sits outside the worker\u0027s trust boundary) could present a self-signed certificate, have the worker complete the STARTTLS handshake silently, and capture the SMTP AUTH credentials and message contents the worker forwarded.\n\nThis CVE covers the **core apache-airflow side** of the same root cause already covered for the SMTP provider by `CVE-2026-41016` (published 2026-04-27, covering `apache-airflow-providers-smtp`). Users who already applied the SMTP-provider fix from CVE-2026-41016 should additionally upgrade `apache-airflow` to 3.2.2 or later to cover the core-side path through `airflow.utils.email`. Affects deployments configured with `smtp_starttls=True` and `smtp_ssl=False` where the SMTP relay is reachable across a less-trusted network segment than the worker.\n\nUsers are advised to upgrade to `apache-airflow` 3.2.2 or later."
        }
      ],
      "metrics": [
        {
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              "text": "low"
            },
            "type": "Textual description of severity"
          }
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      "problemTypes": [
        {
          "descriptions": [
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              "cweId": "CWE-295",
              "description": "CWE-295: Improper Certificate Validation",
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      "providerMetadata": {
        "dateUpdated": "2026-11-03T06:57:48.147Z",
        "orgId": "f0158376-9dc2-43b6-827c-5f631a4d8d09",
        "shortName": "apache"
      },
      "references": [
        {
          "tags": [
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          "url": "https://github.com/apache/airflow/pull/65346"
        },
        {
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            "vendor-advisory"
          ],
          "url": "https://lists.apache.org/thread/6v2ds757000msmjmovnnqryqzks83ps0"
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "Apache Airflow: No certificate validation on SMTP STARTTLS connections",
      "x_generator": {
        "engine": "airflow-s/generate_cve_json.py"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "f0158376-9dc2-43b6-827c-5f631a4d8d09",
    "assignerShortName": "apache",
    "cveId": "CVE-2026-49267",
    "datePublished": "2026-06-01T07:53:13.259Z",
    "dateReserved": "2026-05-28T16:39:15.393Z",
    "dateUpdated": "2026-11-03T06:57:48.147Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

Order JSON

How durations are calculated

Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.

Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.

Publication & reservation Sightings KEV catalogs Other timestamps

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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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