Http4S
CVE-2023-22465
MEDIUM
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A05:2025 - Injection
ASVS 5.0
V2 - Validation and Business Logic Input validation, allowlisting
|
| Impact | CVSS score of 5.3 (MEDIUM). Attack characteristics: network attack vector, low complexity, no privileges required, no user interaction not required. Public proof-of-concept exploit code is available. |
| Exploit ScenarioDerived | This vulnerability can be exploited remotely over the network. Successful exploitation could compromise the medium-severity affected system. |
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Alert meAnalysisAI
Http4s is a Scala interface for HTTP services. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
RemediationAI
No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 5 packages in maven
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified under CWE-20. Http4s is a Scala interface for HTTP services. Starting with version 0.1.0 and prior to versions 0.21.34, 0.22.15, 0.23.17, and 1.0.0-M38, the User-Agent and Server header parsers are susceptible to a fatal error on certain inputs. In http4s, modeled headers are lazily parsed, so this only applies to services that explicitly request these typed headers. Fixes are released in 0.21.34, 0.22.15, 0.23.17, and 1.0.0-M38. As a workaround, use the weakly typed header interface. Affected products include: Typelevel Http4S. Version information: version 0.1.0.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
Http4s is a Scala interface for HTTP services. Starting with version 0.1.0 and prior to versions 0.21.34, 0.22.15, 0.23.17, and 1.0.0-M38, the User-Agent and Server header parsers are susceptible to a fatal error on certain inputs. In http4s, modeled headers are lazily parsed, so this only applies to services that explicitly request these typed headers. Fixes are released in 0.21.34, 0.22.15, 0.23.17, and 1.0.0-M38. As a workaround, use the weakly typed header interface.
Threat Intelligence Overview
NVD
CVE.org
EPSS
GitHub
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.
Affected Products (CPE)NVD
XML External Entity (XXE) injection in http4s-scala-xml's EntityDecoder for scala.xml.Elem (all versions before 0.24.1 a
Http4s client applications that keep a cookie jar can leak stored cookies — including session and authentication cookies
Http4s is a Scala interface for HTTP services. Rated medium severity (CVSS 6.3), this vulnerability is remotely exploita
Request smuggling in the http4s Ember HTTP/1.1 parser lets an unauthenticated, remote attacker bypass front-end access c
Http4s is a minimal, idiomatic Scala interface for HTTP services. Rated critical severity (CVSS 9.1), this vulnerability
HTTP request smuggling in http4s Ember (all releases prior to 0.23.35 and 1.0.0-M47) lets an unauthenticated remote atta
Let me synthesize. CVE-2026-69205: http4s Ember HTTP parser request smuggling via Transfer-Encoding header case-sensiti
http4s is an open source scala interface for HTTP. Rated medium severity (CVSS 4.7), this vulnerability is remotely expl
A crafted WebSocket frame can pin a worker thread and exhaust memory in the http4s Scala HTTP library, causing denial of
Heap exhaustion in the http4s Ember backend (0.23.x before 0.23.35 and 1.0.0 milestones before 1.0.0-M47) allows a singl
Heap-exhaustion denial of service in the http4s DigestAuth server middleware: an inverted stale-nonce comparison in Nonc
Unbounded WebSocket fragment aggregation in http4s-blaze-server allows any client that completes a WebSocket handshake t
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