CVE-2026-7666Potential unencrypted email transmission via STARTTLS in the SMTP backend
- 2.3LowCVSS base score
- 0.15%Exploitation in 30 daysEPSS · top 96% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By DSF
- 33 days later
· 33 days later
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| DSFCNA (assigner) | 4.0 | Low2.3 | 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 |
| DSFCNA (assigner) | 3.1 | Low3.1 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N |
| NVDNVD · Analyzed | 4.0 | Low2.3 | 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 |
- EPSS (exploitation in 30 days)
- 0.15% · top 96% of all CVEs (13 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Low 2.3.
Affected products
- affected 6.0 – < 6.0.6
- unaffected 6.0.6
- affected 5.2 – < 5.2.15
- unaffected 5.2.15
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- PyPIdjangoGHSA-mm6v-q8q9-pgcf (opens in a new tab)
References
References3
- Django security archive (opens in a new tab)vendor-advisory
- Django releases announcements (opens in a new tab)mailing-list
- Django security releases issued: 6.0.6 and 5.2.15 (opens in a new tab)vendor-advisory
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-34087 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-mm6v-q8q9-pgcf (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-7666)Record last updated .