CVE-2026-7666

Description

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.

CVSS v3.1 Score

3.1

LOW

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

EPSS — Exploit Prediction

0.0015

Probability of exploitation

0.05%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-319 CWE-319

Affected Products

Vendor	Product	Versions
djangoproject	django	5.2 — 5.2.15
djangoproject	django	6.0 — 6.0.6

References

Advisories & Patches

https://docs.djangoproject.com/en/dev/releases/security/ https://www.djangoproject.com/weblog/2026/jun/03/security-releases/

Other References

https://groups.google.com/g/django-announce

Frequently Asked Questions

What is CVE-2026-7666? +

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. It has a CVSS v3.1 base score of 3.1 (LOW).

How severe is CVE-2026-7666? +

CVE-2026-7666 has a CVSS v3.1 score of 3.1 out of 10, rated LOW. This is a low-severity vulnerability with limited impact. The EPSS score is 0.0015, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-7666? +

CVE-2026-7666 affects products from djangoproject, specifically: django. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-7666? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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