CVE-2026-69215
Http4s: CookieJar middleware matches by substring, leaking cookies cross-origin
CVSS Score
6.8
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-565 CWE-1275 |
| Vendor | http4s |
| Product | http4s |
| Published | Sep 15, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
None
Availability
None
Affected Versions
http4s / http4s
< 0.23.35 >= 1.0.0-M1, < 1.0.0-M47
References
github.com: https://github.com/http4s/http4s/security/advisories/GHSA-grh8-3p95-f9rr github.com: https://github.com/http4s/http4s/commit/c0a37f38d5ee2a568ba57bd9da62f8d79b8b1fcc github.com: https://github.com/http4s/http4s/releases/tag/v0.23.35 github.com: https://github.com/http4s/http4s/releases/tag/v1.0.0-M47