CVE-2025-14550 Potential denial-of-service vulnerability via repeated headers when using ASGI

High 7.5 Published Updated

Remote attackers can cause denial of service in Django ASGI applications by sending requests with multiple duplicate headers.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
Not needed
Fix
Available

What is CVE-2025-14550?

CVE-2025-14550 is a high-severity denial of service vulnerability in Djangoproject Django, published on 3 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

An issue was discovered in 6.0 before 6.0.2, 5.2 before 5.2.11, and 4.2 before 4.2.28. `ASGIRequest` allows a remote attacker to cause a potential denial-of-service via a crafted request with multiple duplicate headers. 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 Jiyong Yang for reporting this issue.

Weakness: CWE-407

Which versions are affected by CVE-2025-14550?

8 open source packages ship an affected version, including django and Django. It affects 1 product.

PackageAffectedFixed in
django BitnamiFrom 4.2.04.2.28, 5.2.11, 6.0.2
django PyPIFrom 4.24.2.28, 5.2.11, 6.0.2
django PyPIFrom 4.2a14.2.28
django PyPIFrom 5.2a15.2.11
django PyPIFrom 6.0a16.0.2
Django PyPIFrom 4.2a14.2.28
2 more packages
Django PyPIFrom 5.2a15.2.11
Django PyPIFrom 6.0a16.0.2
Linux distribution packages (1)
python-asgiref openSUSE:TumbleweedAll versions3.11.1-1.1

Products include Djangoproject Django.

How do I fix CVE-2025-14550?

Upgrade django to a fixed version for your release line: 4.2.28, 5.2.11 or 6.0.2.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2025-14550 being exploited?

There is no known exploitation of CVE-2025-14550 in the wild and no public exploit code.

All Djangoproject Django vulnerabilities

Sources

Also known as BIT-django-2025-14550, DEBIAN-CVE-2025-14550, ECHO-5865-ae76-0fca, GHSA-33mw-q7rj-mjwj, MINI-x9x3-v97f-fxhp, PYSEC-2026-43 and 1 more.

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