Vulnerability · Published Jun 3, 2026 · Assigned by DSF
CVE-2026-48587Potential exposure of private data via whitespace padding in Vary header
Low 3.1
In plain English
A low-severity security flaw in Django from djangoproject. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 31% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
An issue was discovered in Django 5.2 before 5.2.15 and 6.0 before 6.0.6. `django.utils.cache.has_vary_header()` in Django does not strip leading or trailing whitespace from `Vary` response header values before comparison, which allows remote attackers to read cached responses via requests to URLs whose responses contain whitespace-padded Vary header values. 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 Navid Rezazadeh for reporting this issue.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.24 | py3-django | 5.2.15-r0 | ALPINE-CVE-2026-48587 |
| Debian:12 | python-django | 3:3.2.25-0+deb12u5 | DEBIAN-CVE-2026-48587 |
| Debian:13 | python-django | no fix listed | DEBIAN-CVE-2026-48587 |
| Debian:14 | python-django | 3:5.2.15-1 | DEBIAN-CVE-2026-48587 |
| PyPI | django | 5.2.15, 6.0.6 | PYSEC-2026-198 |
| PyPI | django | 6.0.6 | GHSA-923m-gv2p-w5qp |
| PyPI | django | 5.2.15 | GHSA-923m-gv2p-w5qp |
| Ubuntu:22.04:LTS | python-django | no fix listed | UBUNTU-CVE-2026-48587 |
| Ubuntu:24.04:LTS | python-django | no fix listed | UBUNTU-CVE-2026-48587 |
| Ubuntu:25.10 | python-django | no fix listed | UBUNTU-CVE-2026-48587 |
| Ubuntu:26.04:LTS | python-django | no fix listed | UBUNTU-CVE-2026-48587 |
| Ubuntu:26.10 | python-django | no fix listed | UBUNTU-CVE-2026-48587 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| djangoproject | Django | 6.0 – before 6.0.65.2 – before 5.2.15 |
Weakness: CWE-1023 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N
References
- Django security archive vendor-advisory
- Django releases announcements mailing-list
- Django security releases issued: 6.0.6 and 5.2.15 vendor-advisory