GHSA-799x-qp47-8qwq BIT-airflow-2026-49267 CVE-2026-49267 PYSEC-2026-2346
Apache Airflow has no certificate validation on SMTP STARTTLS connections
- Severity
- 5.9 / 10
- Medium · CVSS 3.1
- Exploit chance (EPSS)
- 0.18%
- Chance of exploitation in the next 30 days. Higher than 8.09% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-295 Improper Certificate Validation
- Fix
3.2.2- Upgrade apache-airflow to this version or later
Description
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.
Affected versions
PyPI
| Package | Vulnerable | Fixed in |
|---|---|---|
| apache-airflow | >= 2.0.0, < 3.2.2 |
3.2.2 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
apache-airflow PyPI → 3.2.2
- pip
pip install --upgrade "apache-airflow>=3.2.2"- poetry
poetry add "apache-airflow>=3.2.2"- uv
uv add "apache-airflow>=3.2.2"
Severity breakdown
CVSS 3.1 5.9
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Weakness
CWE-295: Improper Certificate Validation
The product does not validate, or incorrectly validates, a certificate.
How to prevent it
- Architecture and Design, Implementation: Certificates should be carefully managed and checked to assure that data are encrypted with the intended owner's public key.
- Implementation: If certificate pinning is being used, ensure that all relevant properties of the certificate are fully validated before the certificate is pinned, including the hostname.
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| CVE-2020-13927 Authentication bypass in Apache Airflow | Critical Known exploited | Also affects apache-airflow |
| CVE-2020-11978 Remote code execution (RCE) in Apache Airflow | High Known exploited | Also affects apache-airflow |
| PYSEC-2026-3990 Apache Airflow: the Core API logout endpoint revokes only a session token presented as the _token cookie. | Critical | Also affects apache-airflow |
| PYSEC-2026-3989 When a request to the Airflow core API carries both a session cookie and an explicit `Authorization: Bearer` token, Airflow resolves the caller from the cookie… | Medium | Also affects apache-airflow |
| PYSEC-2026-3988 Apache Airflow's `/assets/events` API returned asset events for every Dag in the deployment, with no filter restricting them to the Dags the caller is… | Medium | Also affects apache-airflow |
| GHSA-5247-m8w9-2v4m Apache Airflow missing team context permits cross-team Dag actions and XCom reads | Medium | Also affects apache-airflow |
| GHSA-f3c2-j7g8-vpp8 Apache Airflow Task SDK fails to mask list-shaped JSON Variables | Medium | Also affects apache-airflow |
| GHSA-cjv4-7hp2-2x9h Apache Airflow bulk endpoints log Variable and Connection secrets in cleartext | Medium | Also affects apache-airflow |
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