Http4s-client_2.12 CVEs with no public exploit

CVE	Severity	Published▾	Status	Exploitation	Description
CVE-2026-69215	Medium	2026-09-15	No exploit published	No public exploit	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.
CVE-2026-69214	Medium	2026-09-15	No exploit published	No public exploit	Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, The CookieJar client middleware stores a response cookie’s Domain attribute without checking that it domain-matches the host that supplied the cookie or rejecting public suffixes. A malicious or compromised server contacted through the same CookieJar can plant a cookie for another domain, and the jar later sends that cookie to the victim domain, enabling session fixation or overwriting security-sensitive cookies. The patch validates the Set-Cookie domain against the response origin, although public-suffix rejection remains unimplemented. This issue is fixed in versions 0.23.35 and 1.0.0-M47.
CVE-2021-41084	High	2021-09-21	No exploit published	No public exploit	http4s is an open source scala interface for HTTP. In affected versions http4s is vulnerable to response-splitting or request-splitting attacks when untrusted user input is used to create any of the following fields: Header names (`Header.name`å), Header values (`Header.value`), Status reason phrases (`Status.reason`), URI paths (`Uri.Path`), URI authority registered names (`URI.RegName`) (through 0.21). This issue has been resolved in versions 0.21.30, 0.22.5, 0.23.4, and 1.0.0-M27 perform the following. As a matter of practice http4s services and client applications should sanitize any user input in the aforementioned fields before returning a request or response to the backend. The carriage return, newline, and null characters are the most threatening.

CVE

Severity

Published▾

Status

Exploitation

Description

CVE-2026-69215

Medium

2026-09-15

No exploit published

No public exploit

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.

CVE-2026-69214

Medium

2026-09-15

No exploit published

No public exploit

Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, The CookieJar client middleware stores a response cookie’s Domain attribute without checking that it domain-matches the host that supplied the cookie or rejecting public suffixes. A malicious or compromised server contacted through the same CookieJar can plant a cookie for another domain, and the jar later sends that cookie to the victim domain, enabling session fixation or overwriting security-sensitive cookies. The patch validates the Set-Cookie domain against the response origin, although public-suffix rejection remains unimplemented. This issue is fixed in versions 0.23.35 and 1.0.0-M47.

CVE-2021-41084

High

2021-09-21

No exploit published

No public exploit

http4s is an open source scala interface for HTTP. In affected versions http4s is vulnerable to response-splitting or request-splitting attacks when untrusted user input is used to create any of the following fields: Header names (`Header.name`å), Header values (`Header.value`), Status reason phrases (`Status.reason`), URI paths (`Uri.Path`), URI authority registered names (`URI.RegName`) (through 0.21). This issue has been resolved in versions 0.21.30, 0.22.5, 0.23.4, and 1.0.0-M27 perform the following. As a matter of practice http4s services and client applications should sanitize any user input in the aforementioned fields before returning a request or response to the backend. The carriage return, newline, and null characters are the most threatening.