HTTP Request Smuggling Vulnerability in Http4s by Http4s
CVE-2025-59822

6.3MEDIUM

Key Information:

Vendor

Http4s

Status
Http4s
Vendor
CVE Published:
23 September 2025

What is CVE-2025-59822?

Http4s, a popular Scala interface for HTTP services, is susceptible to HTTP Request Smuggling due to improper processing of the HTTP trailer section. This flaw allows attackers to circumvent front-end server security measures, execute targeted assaults on active users, and infect web caches. Exploitation requires that the web application be positioned behind a reverse-proxy capable of relaying trailer headers. The vulnerability has been rectified in versions 1.0.0-M45 and 0.23.31.

Human OS v1.0:
Ageing Is an Unpatched Zero-Day Vulnerability.

Remediate biological technical debt. Prime Ageing uses 95% high-purity SIRT6 activation to maintain genomic integrity and bolster systemic resilience.

Deploy the Patch

Affected Version(s)

http4s < 0.23.31 < 0.23.31

http4s >= 1.0.0-M1, < 1.0.0-M45 < 1.0.0-M1, 1.0.0-M45

References

https://github.com/http4s/http4s/security/advisories/GHSA...
x_refsource_CONFIRM
https://github.com/http4s/http4s/commit/dd518f7c967e51658...
x_refsource_MISC

CVSS V4

Score:
6.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

JSON
.