CVE-2026-49267: Apache airflow Apache Airflow Has No Certificate Vulnerability

MODERATE
Advisory Identifier: GHSA-799x-qp47-8qwq
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CVSS 5.9
CWE-295
Published
Advisory Summary

CVE-2026-49267 is a MODERATE (CVSS 5.9) apache airflow has no certificate vulnerability (CWE-295: Improper Certificate Validation) affecting Apache airflow libraries in the PyPI ecosystem. The issue involves apache airflow has no certificate validation on smtp starttls connections. Remediation is available by upgrading affected packages to version 3.2.2.

CVE-2026-49267 at a Glance

CVE Identifier CVE-2026-49267
GHSA Identifier GHSA-799x-qp47-8qwq
Severity MODERATE
CVSS v3.1 Base Score 5.9
CWE Classification CWE-295: Improper Certificate Validation
Affected Product Apache airflow
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 5.9

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2026-49267

To remediate this vulnerability, upgrade all affected Apache airflow dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

apache-airflow fixed: 3.2.2 
pip install apache-airflow>=3.2.2
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show apache-airflow

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-49267, inspect your installed packages using pip:

pip show apache-airflow

Analyze the terminal output to locate any version of Apache airflow in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.2.2), your application is affected.

Note: The pip show apache-airflow command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-295: Improper Certificate Validation, where the product does not validate, or incorrectly validates, a certificate. In Apache airflow, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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.

CVE-2026-49267 Affected Apache airflow Versions

1 component(s)
Fixed Versions:
3.2.2
Product / Package Ecosystem Affected Versions Fixed Version
apache-airflow
pypi/apache-airflow
PyPI
≥ 2.0.0
< 3.2.2
3.2.2

References

NVD — CVE-2026-49267 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-49267
Apache airflow Source Repository REPOSITORY
https://github.com/apache/airflow/pull/65346
Apache airflow Source Repository REPOSITORY
https://github.com/apache/airflow
lists.apache.org/thread/6v2ds757000m... WEB
https://lists.apache.org/thread/6v2ds757000msmjmovnnqryqzks83ps0

Frequently Asked Questions

What is CVE-2026-49267?
CVE-2026-49267 is a security vulnerability in Apache airflow involving Apache Airflow has no certificate validation on SMTP STARTTLS connections under CWE-295: Improper Certificate Validation.
Which Apache airflow versions are affected?
Affected versions include releases prior to 3.2.2 across affected packages: apache-airflow.
What version fixes CVE-2026-49267?
Upgrading to 3.2.2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is apache-airflow affected?
Yes, apache-airflow is affected in releases prior to 3.2.2. Upgrade your dependency to 3.2.2 or later.
What is the CVSS score of CVE-2026-49267?
CVE-2026-49267 has a CVSS v3.1 base score of 5.9 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N.
What CWE is associated with CVE-2026-49267?
CVE-2026-49267 is classified under CWE-295: Improper Certificate Validation (The product does not validate, or incorrectly validates, a certificate.).
How can I check PyPI dependencies for CVE-2026-49267?
Run the dependency tree command: 'pip show apache-airflow'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-799x-qp47-8qwq",
  "modified" : "2026-07-09T21:11:45Z",
  "published" : "2026-06-01T09:31:15Z",
  "aliases" : [ "CVE-2026-49267" ],
  "summary" : "Apache Airflow has 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.\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.",
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  "database_specific" : {
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}