CVE-2025-57783 Improper header parsing may lead to request smuggling
An unauthenticated attacker can exploit improper header parsing in Hiawatha web server to access restricted resources via request smuggling.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-57783?
CVE-2025-57783 is a medium-severity vulnerability in Hiawatha Web server, published on 26 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Improper header parsing may lead to request smuggling has been identified in Hiawatha webserver version 11.7 which allows an unauthenticated attacker to access restricted resources managed by Hiawatha webserver.
Which versions are affected by CVE-2025-57783?
It affects 1 product.
Products include Hiawatha-Webserver Hiawatha.
How do I fix CVE-2025-57783?
No fix has been published for CVE-2025-57783 yet. Limit exposure of the affected software until one is available.
Is CVE-2025-57783 being exploited?
There is no known exploitation of CVE-2025-57783 in the wild and no public exploit code.
Other vulnerabilities in Hiawatha Web server
Sources
Also known as GHSA-mrpv-h52h-rxhw.