VulnerabilityAnalyzed

CVE-2025-59822

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.

MEDIUM 6.3EPSS 0.37%

Does this matter?

Lower severity and a low EPSS score (0.37%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 4.0: 6.3 MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 0.37% probability · 31th percentile
CISA KEV: Not listed
Weakness: CWE-444
Affected: typelevel/http4s
Source: security-advisories@github.com

References

https://github.com/http4s/http4s/commit/dd518f7c967e5165813b8d4a48a82b8fab852d41Patch
https://github.com/http4s/http4s/security/advisories/GHSA-wcwh-7gfw-5wrrExploit, Vendor Advisory
https://github.com/http4s/http4s/security/advisories/GHSA-wcwh-7gfw-5wrrExploit, Vendor Advisory

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.