Cyber Resilience

CVE-2025-59822

MediumPublic PoC

Published: 23 September 2025

Published
23 September 2025
Modified
08 October 2025
KEV Added
—
Patch
—
CVSS Score v4 6.3 CVSS: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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0011 28.6th percentile
Risk Priority 13 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-59822 is a medium-severity HTTP Request/Response Smuggling (CWE-444) vulnerability in Typelevel Http4S. Its CVSS base score is 6.3 (Medium).

Operationally, ranked at the 28.6th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

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…

more

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.

CWE(s)
CWE-444

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

typelevel
http4s
1.0.0 · ≤ 0.23.31

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References