CVE-2025-59822 | Http4s vulnerable to HTTP Request Smuggling due to improper handling of HTTP trailer section

Exp

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.

Published: 2025-09-23 Last update: 2025-10-08 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-59822 is rated Exploit Available (50/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.34%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2025-59822

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2025-59822

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.06% 0.34% +0.29%
2 2025-11-04 0.04% 0.06% +0.02%
3 2025-10-09 — 0.04% —

Full EPSS history (5 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-59822

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.3 4.0 MEDIUM
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 Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network.
Attack complexity (AC:L)
Exploitation conditions are straightforward and stable.
Attack requirements (AT:P)
Additional preconditions must be present for exploitation.
Privileges required (PR:N)
No privileges are required.
User interaction (UI:N)
No user interaction is required.
Vulnerable system confidentiality impact (VC:N)
No confidentiality impact on the vulnerable system.
Vulnerable system integrity impact (VI:L)
Limited integrity impact on the vulnerable system.
Vulnerable system availability impact (VA:N)
No availability impact on the vulnerable system.
Subsequent system confidentiality impact (SC:N)
No confidentiality impact on subsequent systems.
Subsequent system integrity impact (SI:N)
No integrity impact on subsequent systems.
Subsequent system availability impact (SA:N)
No availability impact on subsequent systems.
Exploit maturity (threat) (E:X)
Not defined: no reliable threat intelligence; scoring assumes the worst case (equivalent to Attacked).
Confidentiality requirement (CR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Integrity requirement (IR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Availability requirement (AR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Modified attack vector (MAV:X)
Not defined: scoring uses the Base Attack Vector (AV).
Modified attack complexity (MAC:X)
Not defined: scoring uses the Base Attack Complexity (AC).
Modified attack requirements (MAT:X)
Not defined: scoring uses the Base Attack Requirements (AT).
Modified privileges required (MPR:X)
Not defined: scoring uses the Base Privileges Required (PR).
Modified user interaction (MUI:X)
Not defined: scoring uses the Base User Interaction (UI).
Modified vulnerable system confidentiality impact (MVC:X)
Not defined: scoring uses the Base VC metric.
Modified vulnerable system integrity impact (MVI:X)
Not defined: scoring uses the Base VI metric.
Modified vulnerable system availability impact (MVA:X)
Not defined: scoring uses the Base VA metric.
Modified subsequent system confidentiality impact (MSC:X)
Not defined: scoring uses the Base SC metric.
Modified subsequent system integrity impact (MSI:X)
Not defined: scoring uses the Base SI metric.
Modified subsequent system availability impact (MSA:X)
Not defined: scoring uses the Base SA metric.
Safety (supplemental) (S:X)
Not evaluated.
Automatable (supplemental) (AU:X)
Not evaluated.
Recovery (supplemental) (R:X)
Not evaluated.
Value density (supplemental) (V:X)
Not evaluated.
Vulnerability response effort (supplemental) (RE:X)
Not evaluated.
Provider urgency (supplemental) (U:X)
Not evaluated.
 — — [email protected]
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2025-59822

GitHub Security Advisory for CVE-2025-59822

GHSA-wcwh-7gfw-5wrr · Severity: medium · Ecosystem: maven — Http4s vulnerable to HTTP Request Smuggling due to improper handling of HTTP trailer section

Affected software / configurations for CVE-2025-59822

Vendor Product Version Raw CPE
typelevel http4s < 0.23.31 cpe:2.3:a:typelevel:http4s:*:*:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone1:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone10:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone11:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone12:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone13:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone14:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone15:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone16:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone17:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone18:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone19:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone2:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone20:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone21:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone22:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone23:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone24:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone25:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone26:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone27:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone28:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone29:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone3:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone30:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone31:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone32:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone33:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone34:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone35:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone36:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone37:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone38:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone39:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone4:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone40:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone41:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone42:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone43:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone44:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone5:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone6:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone7:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone8:*:*:*:*:*:*
typelevel http4s 1.0.0 cpe:2.3:a:typelevel:http4s:1.0.0:milestone9:*:*:*:*:*:*

References for CVE-2025-59822

cvelogic Threat Intelligence