Predictive Vulnerability Intelligence.

Product

  • Product
  • Pricing
  • Documentation

Company

  • About
  • Partnerships
  • Blog
  • Support

Legal

  • Terms
  • Privacy
  • Data Licensing

© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2023-22465

20
FAUCET Score

CVE-2023-22465 is a denial-of-service vulnerability affecting Http4s, a Scala HTTP services interface, in versions prior to 0.21.34, 0.22.15, 0.23.17, and 1.0.0-M38. Specifically, malformed User-Agent or Server headers can cause a fatal error if explicitly requested by the service. Rated CVSS 5.3 MEDIUM, this vulnerability has a low attack complexity and requires no privileges, but only impacts availability. There is currently no evidence of active exploitation, public exploit code, or significant community discussion surrounding this CVE.

Impacted Technologies

VendorProductVersion(s)CPE
>= 0.1.0, < 0.21.34CPE matchmatch criteria
cpe:2.3:a:typelevel:http4s:*:*:*:*:*:*:*:*
>= 0.22.0, < 0.22.15CPE matchmatch criteria
cpe:2.3:a:typelevel:http4s:*:*:*:*:*:*:*:*
>= 0.23.0, < 0.23.17CPE matchmatch criteria
cpe:2.3:a:typelevel:http4s:*:*:*:*:*:*:*:*
1.0.0CPE matchmatch criteria
cpe:2.3:a:typelevel:http4s:1.0.0:milestone1:*:*:*:*:*:*
1.0.0CPE matchmatch criteria
cpe:2.3:a:typelevel:http4s:1.0.0:milestone10:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

7.5HIGH

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

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
Exploitability Score
3.9
Impact Score
3.6
CvssVersion
3.1

Exploit Intelligence

EPSS Score
0.84%
Probability of exploitation in next 30 days
EPSS Percentile
54.2%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0084 is in the 34th percentile among its peer group of 23,705 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.0 Mastodon, and 0.4 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.0 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (8)

mavenpatch availablevia ghsa
Product: org.http4s:http4s-core_2.13Fixed in: 0.21.34
mavenpatch availablevia ghsa
Product: org.http4s:http4s-core_2.13Fixed in: 0.22.15
mavenpatch availablevia ghsa
Product: org.http4s:http4s-core_2.13Fixed in: 0.23.17
mavenpatch availablevia ghsa
Product: org.http4s:http4s-core_2.13Fixed in: 1.0.0-M38
mavenpatch availablevia ghsa
Product: org.http4s:http4s-core_2.12Fixed in: 0.21.34
mavenpatch availablevia ghsa
Product: org.http4s:http4s-core_2.12Fixed in: 0.22.15
mavenpatch availablevia ghsa
Product: org.http4s:http4s-core_2.12Fixed in: 0.23.17
github_advisoryworkaround availablevia nvd_reference
View patch

Vendor Advisories (1)

mavenGHSA-54w6-vxfh-fw7fhigh

Http4s improperly parses User-Agent and Server headers

Jan 6, 2023

References

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