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VulnerabilityPublished

CVE-2026-41016: Apache Airflow Providers SMTP · Improper Certificate Validation

Affects Apache Airflow Providers SMTPSource CVE Database V5

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Not known to be exploited · CVSS 5.9 Medium : upgrade to 3.0.0 when convenient.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score
5.9Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.2% chance of exploitation in 30 days – higher than 18% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 3.0.0
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 30 Apr 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

What to do

Upgrade Apache Airflow Providers SMTP to 3.0.0.

Affected software

ProductAffectedFixed in
Apache Software FoundationApache Airflow Providers SMTPAffected
  • >=2.0.0 <3.0.0
Fixed in
  • 3.0.0
PyPIapache-airflow-providers-smtppkg:pypi/apache-airflow-providers-smtpOther threatsAffected
  • =2.0.0
Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Until then, consider restricting network access between Airflow workers and SMTP servers to trusted networks to reduce the risk of man-in-the-middle attacks.

Description

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-smtp` version that contains the fix.

References

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