CVE-2026-7666 LOW

CVE-2026-7666: Potential unencrypted email transmission via STARTTLS in the SMTP backend

Vendor Djangoproject
Product Django
Weakness CWE-319 · Cleartext transmission
Published June 3, 2026
Last update June 3, 2026

CVSS base score

3.1/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction Required
Confidentiality Low
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N

What the vulnerability does

01Description

An issue was discovered in Django 6.0 before 6.0.6 and 5.2 before 5.2.15. `django.core.mail.backends.smtp.EmailBackend` in Django fails to prevent reuse of a partially-initialized connection after a failed `STARTTLS` handshake when `fail_silently=True`, which allows on-path network attackers to read email content via cleartext interception. Earlier, unsupported Django series (such as 5.0.x, 4.1.x, and 3.2.x) were not evaluated and may also be affected. Django would like to thank Kasper Dupont for reporting this issue.

Key dates

02Disclosure timeline

June 3, 2026 CVE published
June 3, 2026 Record updated