CVE-2025-59822

HIGH

Published Sep 23, 2025 Modified Oct 8, 2025 CWE-444

Description

Http4s is a Scala interface for HTTP services. In versions from 1.0.0-M1 to before 1.0.0-M45 and before 0.23.31, http4s is vulnerable to HTTP Request Smuggling due to improper handling of HTTP trailer section. This vulnerability could enable attackers to bypass front-end servers security controls, launch targeted attacks against active users, and poison web caches. A pre-requisite for exploitation involves the web application being deployed behind a reverse-proxy that forwards trailer headers. This issue has been patched in versions 1.0.0-M45 and 0.23.31.

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CVSS v3.1 Score

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Weakness Type (CWE)

CWE-444 CWE-444

Affected Products

Vendor	Product	Versions
typelevel	http4s	< 0.23.31
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All
typelevel	http4s	All

References

Advisories & Patches

https://github.com/http4s/http4s/commit/dd518f7c967e5165813b8d4a48a82b8fab852d41 https://github.com/http4s/http4s/security/advisories/GHSA-wcwh-7gfw-5wrr https://github.com/http4s/http4s/security/advisories/GHSA-wcwh-7gfw-5wrr

Exploits

https://github.com/http4s/http4s/security/advisories/GHSA-wcwh-7gfw-5wrr https://github.com/http4s/http4s/security/advisories/GHSA-wcwh-7gfw-5wrr

Frequently Asked Questions

What is CVE-2025-59822? +

How severe is CVE-2025-59822? +

CVE-2025-59822 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2025-59822? +

CVE-2025-59822 affects products from typelevel, specifically: http4s. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-59822? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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