CVE-2026-32794: TLS Certificate Verification Bypass in Apache Airflow Databricks Provider

Keywords: TLS, certificate verification, MITM, Kubernetes, Databricks, OAuth, CWE-295, Apache Airflow

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Table of Contents

• Overview
• Vulnerability Details
• Technical Analysis
• Attack Chain
• Impact
• Remediation
• Timeline
• References
• Contact
• Disclaimer

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Overview

The apache-airflow-providers-databricks package disables TLS certificate verification when communicating with the Kubernetes API server during federated token exchange. Both the synchronous and asynchronous code paths use verify=False / ssl=False, allowing any attacker with network access within the K8s cluster to MITM the connection and steal both the in-cluster service account JWT and the Databricks OAuth token.

The code comments claim "K8s in-cluster uses self-signed certs," but this is incorrect. Kubernetes provides a CA bundle at /var/run/secrets/kubernetes.io/serviceaccount/ca.crt specifically for this purpose.

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Vulnerability Details

Field	Value
CVE	CVE-2026-32794
CWE	CWE-295: Improper Certificate Validation
Package	apache-airflow-providers-databricks (pip)
Affected Versions	All versions with K8s token exchange
Patched Version	Pending (PR #63704)
Component	providers/databricks/src/airflow/providers/databricks/hooks/databricks_base.py

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Technical Analysis

Vulnerable Code

Line 699 (sync path) - _get_k8s_token_request_api():

resp = requests.post(
    token_request_url,
    headers={
        "Authorization": f"Bearer {in_cluster_token}",
        "Content-Type": "application/json",
    },
    json=self._build_k8s_token_request_payload(audience, expiration_seconds),
    verify=False,  # K8s in-cluster uses self-signed certs
    timeout=self.token_timeout_seconds,
)

Line 764 (async path) - _a_get_k8s_token_request_api():

async with self._session.post(
    token_request_url,
    ...
    ssl=False,  # K8s in-cluster uses self-signed certs
)

The Core Issue

The comment says "K8s in-cluster uses self-signed certs" but Kubernetes provides a trusted CA bundle at a well-known path. The correct approach is to use that CA bundle for verification rather than disabling TLS entirely.

Secure Pattern

K8S_CA_CERT_PATH = "/var/run/secrets/kubernetes.io/serviceaccount/ca.crt"

# Sync
resp = requests.post(token_request_url, ..., verify=K8S_CA_CERT_PATH)

# Async
ssl_ctx = ssl.create_default_context(cafile=K8S_CA_CERT_PATH)
async with self._session.post(token_request_url, ..., ssl=ssl_ctx)

---

Attack Chain

+----------------------------------------------------------+
|  1. ATTACKER GAINS POD ACCESS                            |
|     Compromised container or network namespace access     |
+---------------------------+------------------------------+
                            |
                            v
+----------------------------------------------------------+
|  2. MITM THE TOKEN EXCHANGE                              |
|     ARP spoof / DNS hijack within cluster network         |
|     Serve self-signed cert (accepted due to verify=False) |
+---------------------------+------------------------------+
                            |
                            v
+----------------------------------------------------------+
|  3. INTERCEPT CREDENTIALS                                |
|     - K8s service account JWT (Authorization header)      |
|     - Databricks OAuth token (response body)              |
+---------------------------+------------------------------+
                            |
                            v
+----------------------------------------------------------+
|  4. LATERAL MOVEMENT                                     |
|     Use stolen tokens for K8s API + Databricks access     |
+----------------------------------------------------------+

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Impact

Aspect	Description
Direct Impact	MITM interception of K8s JWT and Databricks OAuth tokens
Attack Surface	Any pod within the same cluster network
Credential Theft	Both K8s service account and Databricks tokens exposed
Lateral Movement	Stolen tokens enable access to both K8s API and Databricks workspace
Affected Users	Any Airflow deployment using Databricks provider with K8s token exchange

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Remediation

Fix PR: apache/airflow#63704

The fix replaces verify=False with verify=K8S_CA_CERT_PATH using the standard Kubernetes in-cluster CA bundle, and replaces ssl=False with a properly configured SSL context.

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Timeline

Date	Event
2026-03-15	Vulnerability reported to security@airflow.apache.org
2026-03-15	Jarek Potiuk (Airflow committer) acknowledged the report
2026-03-16	CVE-2026-32794 allocated; fix PR #63704 opened

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References

• CVE-2026-32794
• Fix PR: apache/airflow#63704
• CWE-295: Improper Certificate Validation
• Apache Airflow Security Policy

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Contact

• Website: snailsploit.com
• GitHub: @SnailSploit
• LinkedIn: /in/kaiaizen

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Disclaimer

This advisory is published for educational and defensive purposes under responsible disclosure principles. The information provided is intended to help developers and security teams understand and remediate the vulnerability. Do not use this information for unauthorized testing or malicious purposes.