Skip to content
Fencer Vulns
low 3.1

CVE-2026-7666 json

Potential unencrypted email transmission via STARTTLS in the SMTP backend

published 2026-06-03 5 mo ago modified 2026-09-10 59 d ago also BIT-django-2026-7666 , EUVD-2026-34087 , GHSA-mm6v-q8q9-pgcf , PYSEC-2026-200

cvss
3.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 4%
public exploits
0
none known

Summary

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.

Patch / fix

  • pypi django 5.2.15, 6.0.6
  • bitnami django 5.2.15, 6.0.6
  • djangoproject Django 5.2.15, 6.0.6
  • python-django Debian 14 3:5.2.15-1

debian advisories DEBIAN-CVE-2026-7666

  • python-Django SLE Module for Package Hub 15 SP7 4.2.11-150600.3.59.1

suse advisories SUSE-SU-2026:2318-1

  • python-Django5 openSUSE Tumbleweed 5.2.16-1.1
  • python-Django openSUSE Tumbleweed 5.2.15-1.1
  • python-Django6 openSUSE Tumbleweed 6.0.6-1.1
  • python-Django openSUSE Leap 16.0 5.2.4-bp160.9.1
  • python-Django4 openSUSE Tumbleweed 4.2.30-3.1

opensuse advisories openSUSE-SU-2026:11270-1openSUSE-SU-2026:11002-1openSUSE-SU-2026:11003-1openSUSE-SU-2026:20937-1openSUSE-SU-2026:10989-1

  • py3-django Alpine 3.24 5.2.15-r0

alpine advisories ALPINE-CVE-2026-7666

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-7666 updated cvss 3.1

django: Django: Information disclosure via failed STARTTLS handshake in EmailBackend

  • Red Hat Ansible Automation Platform 2 automation-controller, ansible-automation-platform-26/hub-rhel9, ansible-automation-platform-27/hub-rhel9, ansible-automation-platform-26/gateway-rhel9, ansible-automation-platform-27/gateway-rhel9, ansible-automation-platform-24/lightspeed-rhel8, +11 more Red Hat Discovery 2 discovery/discovery-server-rhel9 Red Hat Satellite 6 satellite/iop-advisor-backend-rhel9
    affected: workaround, no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
5 mo ago

Exploit prediction

0.15% chance of exploitation in the next 30 days, higher than 4% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 3.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N
CNA 4.0 2.3 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
GitHub 3.1 3.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N
CNA 4.0 2.3 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

Affected packages

ecosystem package affected fixed in
pypi django
>=5.2, <5.2.15
>=6.0, <6.0.6
5.2.15
6.0.6
bitnami django
>=5.2.0, <5.2.15
>=6.0.0, <6.0.6
5.2.15
6.0.6

Affected products

  • djangoproject Django

Classification

Weakness
  • CWE-319 Cleartext Transmission of Sensitive Information
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.