← Vulnerability feed

Vulnerability record · CVE-2023-22465 · published 4 January 2023

CVE-2023-22465: Typelevel http4s improper input validation vulnerability

Typelevel · Http4s

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.

5.3 CVSS 3.1 Medium EPSS 0.85% · top 43.7% CWE-20 · Improper input validation
5.3CVSS 3.1 base score
0.85%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References, 2 tagged exploit
17 Jun 2026Last modified by NVD

Description

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.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/http4s/http4s/security/advisories/GHSA-54w6-vxfh-fw7f ExploitMitigationThird Party Advisory
https://github.com/http4s/http4s/security/advisories/GHSA-54w6-vxfh-fw7f ExploitMitigationThird Party Advisory

Track CVE-2023-22465 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.1CVE-2021-39185Typelevel http4s origin validation error vulnerabilityHttp4s is a minimal, idiomatic Scala interface for HTTP services. In http4s versions 0.21.26 and prior, 0.22.0 through 0.22.2, 0.23.0, 0.23.1, and 1.…EPSS 0.59%7.5CVE-2021-21294Typelevel http4s uncontrolled resource consumption vulnerabilityHttp4s (http4s-blaze-server) is a minimal, idiomatic Scala interface for HTTP services. Http4s before versions 0.21.17, 0.22.0-M2, and 1.0.0-M14 have…EPSS 2.1%7.5CVE-2020-5280Typelevel http4s relative path traversal vulnerabilityhttp4s before versions 0.18.26, 0.20.20, and 0.21.2 has a local file inclusion vulnerability. This vulnerability applies to all users of org.http4s.s…EPSS 7.0%6.3CVE-2025-59822Typelevel http4s http request smuggling vulnerabilityHttp4s 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…EPSS 0.37%5.8CVE-2021-32643Typelevel http4s path traversal vulnerabilityHttp4s is a Scala interface for HTTP services. `StaticFile.fromUrl` can leak the presence of a directory on a server when the `URL` scheme is not `fi…EPSS 1.4%4.7CVE-2021-41084Typelevel http4s server-side request forgery (ssrf) vulnerabilityhttp4s is an open source scala interface for HTTP. In affected versions http4s is vulnerable to response-splitting or request-splitting attacks when …EPSS 1.2%9.5CVE-2026-88771Citrix NetScaler Improper Input Validation VulnerabilityImproper input validation vulnerability in Citrix NetScaler ADC and Citrix NetScaler Gateway. This issue affects ADC: before 14.1-73.37, before 13.1-…KEV9.5CVE-2026-93952Arista velocloud orchestrator improper input validation vulnerabilityVeloCloud Orchestrator (VCO) on-prem has a security issue where this issue may allow a remote attacker to access privileged internal functionality an…KEVEPSS 0.90%

Source: NIST National Vulnerability Database (record CVE-2023-22465), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.