Skip to main content

Http4S CVE-2026-69215

| EUVDEUVD-2026-79191 MEDIUM
Reliance on Cookies without Validation and Integrity Checking (CWE-565)
2026-09-15 GitHub_M GHSA-grh8-3p95-f9rr
6.8
CVSS 3.1 · Vendor: GitHub_M
View

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A08:2025 - Software or Data Integrity Failures
ASVS 5.0
V3 - Web Frontend Security Cookie integrity validation
This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).
Patch available 0.4% exploitation probability (EPSS)

Get an e-mail when this CVE is exploited, patched or re-scored. Free account.

Alert me

AnalysisAIv1 – Sep 15, 2026

Http4s client applications that keep a cookie jar can leak stored cookies — including session and authentication cookies — to attacker-controlled hosts because versions prior to 0.23.35 and 1.0.0-M47 decide cookie applicability with unanchored substring checks instead of RFC 6265 domain and path matching. A cookie scoped to example.com is therefore also attached to requests for evilexample.com, api.example.com.attacker.net, or an unrelated path, so any attacker who can influence the outbound URL the application requests receives the cookie and can hijack that outbound session. The flaw is fixed in 0.23.35 and 1.0.0-M47; no public exploit code and no CISA KEV entry were identified at time of analysis.

Affected VersionsENISA

http4s < 0.23.35
http4s 1.0.0-M1, < 1.0.0-M47

Affected Packages

maven org.http4s:http4s-client_2.12 fix: 0.23.35
maven org.http4s:http4s-client_2.13 fix: 0.23.35, 1.0.0-M47
maven org.http4s:http4s-client_3 fix: 0.23.35, 1.0.0-M47
euvd http4s fix: 0.23.35
euvd http4s_1_0_0_m1 fix: 1.0.0-M47

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 5 packages in maven, euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Know when Http4S gets its next vulnerability

  • Watch products and get an email when something new is published
  • Check this CVE against your own stack and servers
  • Exploit and PoC references, threat intelligence from 22 sources

No credit card · 7-day full trial

Severity by source

Vendor (GitHub_M) PRIMARY 6.8 MEDIUM
AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N

Primary rating from Vendor (GitHub_M) · only source for this CVE.

CVSS VectorVendor: GitHub_M

Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
None
Availability
None

Lifecycle Timeline

1
Patch available
Sep 15, 2026 - 20:19 EUVD

DescriptionCVE.org

Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, The CookieJar client middleware uses unanchored substring checks instead of RFC 6265 domain and path matching when deciding whether to attach a stored cookie. A cookie for example.com can consequently be sent to an attacker-controlled hostname such as evilexample.com when an application using the same jar makes an attacker-influenced outbound request. This exposes session or authentication cookies and can enable hijacking of the application’s outbound sessions. This issue is fixed in versions 0.23.35 and 1.0.0-M47.

Threat Intelligence Overview

EPSS Score
0.4%
Top 64% exploitable
Threat Intel
1
1 source
Exploit
POC
Public exploit code exists
Data Quality
5 sources
Confidence: Medium

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.

SignalValue
Severity MEDIUM
CISA KEV No
Public POC Yes
EPSS 0.4%
Patch available Yes
Active threat No
Deciding rule
MEDIUM severity (CVSS 4.0-6.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Scheduled
Exploitation· derived
Poc
System Exposure· derived
Open
Automatable· derived
No
Human Impact· derived
Medium

Priority Score

54
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +34
PoC: +20
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.

More in Http4S

View all
CVE-2026-61741 CRITICAL POC
9.3 Sep 24

XML External Entity (XXE) injection in http4s-scala-xml's EntityDecoder for scala.xml.Elem (all versions before 0.24.1 a

CVE-2025-59822 MEDIUM POC
6.3 Sep 23

Http4s is a Scala interface for HTTP services. Rated medium severity (CVSS 6.3), this vulnerability is remotely exploita

CVE-2023-22465 MEDIUM POC
5.3 Jan 04

Http4s is a Scala interface for HTTP services. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploita

CVE-2026-69204 CRITICAL
9.2 Sep 15

Request smuggling in the http4s Ember HTTP/1.1 parser lets an unauthenticated, remote attacker bypass front-end access c

CVE-2021-39185 CRITICAL
9.1 Sep 01

Http4s is a minimal, idiomatic Scala interface for HTTP services. Rated critical severity (CVSS 9.1), this vulnerability

CVE-2026-69217 HIGH
8.7 Sep 15

HTTP request smuggling in http4s Ember (all releases prior to 0.23.35 and 1.0.0-M47) lets an unauthenticated remote atta

CVE-2026-69205 HIGH
8.7 Sep 15

Let me synthesize. CVE-2026-69205: http4s Ember HTTP parser request smuggling via Transfer-Encoding header case-sensiti

CVE-2021-41084 MEDIUM POC
4.7 Sep 21

http4s is an open source scala interface for HTTP. Rated medium severity (CVSS 4.7), this vulnerability is remotely expl

CVE-2026-69210 HIGH
7.5 Sep 15

A crafted WebSocket frame can pin a worker thread and exhaust memory in the http4s Scala HTTP library, causing denial of

CVE-2026-69203 HIGH
7.5 Sep 15

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

CVE-2026-69208 HIGH
7.5 Sep 15

Heap-exhaustion denial of service in the http4s DigestAuth server middleware: an inverted stale-nonce comparison in Nonc

CVE-2026-73493 HIGH
7.5 Aug 12

Unbounded WebSocket fragment aggregation in http4s-blaze-server allows any client that completes a WebSocket handshake t

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy