Bug 2484369 (CVE-2026-7666)

Summary:	CVE-2026-7666 django: Django: Information disclosure via failed STARTTLS handshake in EmailBackend
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	anthomas, brasmith, cmyers, cochase, dnakabaa, dranck, dschmidt, ehelms, erezende, ggainey, jlanda, jmitchel, juwatts, jwong, kaycoth, kshier, lcouzens, mhulan, nmoumoul, omaciel, osousa, pbohmill, pcreech, rchan, simaishi, smallamp, smcdonal, stcannon, teagle, tmalecek, ttakamiy, yguenane
Target Milestone:	---	Keywords:	Security
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Hardware:	All
OS:	Linux
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Doc Text:	A flaw was found in Django. An on-path network attacker could exploit a vulnerability in `django.core.mail.backends.smtp.EmailBackend` where a partially-initialized connection is reused after a failed `STARTTLS` handshake when `fail_silently=True`. This could allow the attacker to intercept and read email content, leading to information disclosure.	Story Points:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-06-03 15:01:28 UTC

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.