Email disclosure via pre-TLS SMTP connection reuse
Published Jun 3, 2026 · Updated Jun 3, 2026
Cleartext transmission in Django 5.2 before 5.2.15 and 6.0 before 6.0.6 allows man-in-the-middle attackers to read email content. EmailBackend assigned its SMTP connection before STARTTLS completed, so fail_silently=True left the pre-TLS connection available for later sendmail use. Exploitation requires EMAIL_USE_TLS, a failed STARTTLS handshake, silent failure handling, and an on-path position; EMAIL_USE_SSL connections are unaffected.
Summary
What happened
Cleartext transmission in Django 5.2 before 5.2.15 and 6.0 before 6.0.6 allows man-in-the-middle attackers to read email content. EmailBackend assigned its SMTP connection before STARTTLS completed, so fail_silently=True left the pre-TLS connection available for later sendmail use. Exploitation requires EMAIL_USE_TLS, a failed STARTTLS handshake, silent failure handling, and an on-path position; EMAIL_USE_SSL connections are unaffected.
The record
- CVE
- CVE-2026-7666
- Published
- Jun 3, 2026
- Updated
- Jun 3, 2026
- Vendor
- Django Software Foundation
- Product
- Django
- Classifications
- CWE-319, T1557
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 3, 2026CVE publishedPublication date reported by the CVE source.
- Jun 3, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=5.2 <5.2.15
- Affected versionversion=6.0 <6.0.6
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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