CVE-2026-41016: Apache Airflow's SMTP provider `SmtpHook` called Python's `smtplib.SMTP.starttls()` without an SSL context, so

Routine

MEDIUM 5.9REMOTEWATCHLISTUPGRADE

CVE-2026-41016 is a medium-severity flaw (CVSS 5.9) affecting airflow. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Apache Airflow's SMTP provider `SmtpHook` called Python's `smtplib.SMTP.starttls()` without an SSL context, so no certificate validation was performed on the TLS upgrade. A man-in-the-middle between the Airflow worker and the SMTP server could present a self-signed certificate, complete the STARTTLS upgrade, and capture the SMTP credentials sent during the subsequent `login()` call. Users are advised to upgrade to the `apache-airflow-providers-sm

Why this priority

Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	5.9 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 81%)
CISA exploited list	No
Weakness	CWE-295
Published	2026-04-30
Last modified	2026-10-26

Publisher (CNA): Apache Software Foundation · Vendor: apache

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-30 10:16 UTCPublished CVE record published
2026-10-26 21:10 UTCUpdated Record last modified

apache airflow UPGRADE

Affected: >= 2.0.0 and < 3.0.0

Fixed in: 3.0.0

Safe to downgrade to: a release before 2.0.0

1. Check installed version

apt-cache policy airflow || rpm -q airflow || airflow --version

2. UPGRADE to 3.0.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade airflow

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade airflow

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 2.0.0 (Debian / Ubuntu)

apt-cache madison airflow sudo apt install airflow=<VERSION_BEFORE_2.0.0> sudo apt-mark hold airflow

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list airflow sudo dnf downgrade airflow-<VERSION_BEFORE_2.0.0> sudo dnf versionlock add airflow

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-41016?

airflow: upgrade to 3.0.0. Exact commands for each OS are on this page.

Is CVE-2026-41016 being exploited?

CVE-2026-41016 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-41016 affect?

CVE-2026-41016 affects airflow. Severity is medium (CVSS 5.9). Apache Airflow's SMTP provider `SmtpHook` called Python's `smtplib.SMTP.starttls()` without an SSL context, so no certificate validation was performed on the TLS upgrade. A man-in-the-middle between the Airflow worker and the SMTP server co

How urgent is CVE-2026-41016?

Priority 35/100. Remotely exploitable, no login, no user action; On your watchlist

Software pages

Python vulnerabilities · Apache Airflow vulnerabilities

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References

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