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.

CVSS v3 3.1 LOW

3.1^/10

CVSS v3 : LOW

Vector :

Exploitability : 1.6 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact LOW

Integrity Impact NONE

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://docs.djangoproject.com/en/dev/releases/security/	Patch Vendor Advisory
https://groups.google.com/g/django-announce	Release Notes
https://www.djangoproject.com/weblog/2026/jun/03/security-releases/	Patch Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:djangoproject:django::::::::
	cpe:2.3:a:djangoproject:django::::::::

History

No history.

Information

Published : 2026-06-03 14:16

Updated : 2026-07-21 19:10

NVD link : CVE-2026-7666

Mitre link : CVE-2026-7666

CVE.ORG link : CVE-2026-7666

JSON object : View

Products Affected

djangoproject

django

CWE

CWE-319

Cleartext Transmission of Sensitive Information

{"id": "CVE-2026-7666", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-7666", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-06-03T15:43:26.714914Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "6a34fbeb-21d4-45e7-8e0a-62b95bc12c92", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 3.1, "attackVector": "NETWORK", "baseSeverity": "LOW", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N", "integrityImpact": "NONE", "userInteraction": "REQUIRED", "attackComplexity": "HIGH", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "LOW"}, "impactScore": 1.4, "exploitabilityScore": 1.6}], "cvssMetricV40": [{"type": "Secondary", "source": "6a34fbeb-21d4-45e7-8e0a-62b95bc12c92", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 2.3, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "LOW", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "PASSIVE", "attackComplexity": "HIGH", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "NONE", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "LOW", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "affected": [{"source": "6a34fbeb-21d4-45e7-8e0a-62b95bc12c92", "affectedData": [{"repo": "https://github.com/django/django/", "vendor": "djangoproject", "product": "Django", "versions": [{"status": "affected", "version": "6.0", "lessThan": "6.0.6", "versionType": "python"}, {"status": "unaffected", "version": "6.0.6", "versionType": "python"}, {"status": "affected", "version": "5.2", "lessThan": "5.2.15", "versionType": "python"}, {"status": "unaffected", "version": "5.2.15", "versionType": "python"}], "packageName": "django", "collectionURL": "https://pypi.org/project/Django/", "defaultStatus": "unaffected"}]}], "published": "2026-06-03T14:16:47.087", "references": [{"url": "https://docs.djangoproject.com/en/dev/releases/security/", "tags": ["Patch", "Vendor Advisory"], "source": "6a34fbeb-21d4-45e7-8e0a-62b95bc12c92"}, {"url": "https://groups.google.com/g/django-announce", "tags": ["Release Notes"], "source": "6a34fbeb-21d4-45e7-8e0a-62b95bc12c92"}, {"url": "https://www.djangoproject.com/weblog/2026/jun/03/security-releases/", "tags": ["Patch", "Vendor Advisory"], "source": "6a34fbeb-21d4-45e7-8e0a-62b95bc12c92"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "6a34fbeb-21d4-45e7-8e0a-62b95bc12c92", "description": [{"lang": "en", "value": "CWE-319"}]}], "descriptions": [{"lang": "en", "value": "An issue was discovered in Django 6.0 before 6.0.6 and 5.2 before 5.2.15.\n`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.\nEarlier, unsupported Django series (such as 5.0.x, 4.1.x, and 3.2.x) were not evaluated and may also be affected.\nDjango would like to thank Kasper Dupont for reporting this issue."}, {"lang": "es", "value": "Se descubri\u00f3 un problema en Django 6.0 anterior a 6.0.6 y 5.2 anterior a 5.2.15.\n'django.core.mail.backends.smtp.EmailBackend' en Django falla al evitar la reutilizaci\u00f3n de una conexi\u00f3n parcialmente inicializada despu\u00e9s de un handshake 'STARTTLS' fallido cuando 'fail_silently=True', lo que permite a atacantes de red en la ruta leer el contenido del correo electr\u00f3nico mediante intercepci\u00f3n de texto claro.\nSeries de Django anteriores no soportadas (como 5.0.x, 4.1.x y 3.2.x) no fueron evaluadas y tambi\u00e9n podr\u00edan estar afectadas.\nDjango desea agradecer a Kasper Dupont por reportar este problema."}], "lastModified": "2026-07-21T19:10:00.107", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:djangoproject:django:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "048C450F-F81F-4A1D-9BF7-DC36FF26988E", "versionEndExcluding": "5.2.15", "versionStartIncluding": "5.2"}, {"criteria": "cpe:2.3:a:djangoproject:django:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "BC9BA685-D9CE-406E-A479-9C444E8EADB3", "versionEndExcluding": "6.0.6", "versionStartIncluding": "6.0"}], "operator": "OR"}]}], "sourceIdentifier": "6a34fbeb-21d4-45e7-8e0a-62b95bc12c92"}