Vulnerability · Published Sep 15, 2026 · Assigned by GitHub_M
CVE-2026-69215Http4s: CookieJar middleware matches by substring, leaking cookies cross-origin
Medium 6.8
In plain English
A medium-severity security flaw in http4s from http4s. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 43% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Maven | org.http4s:http4s-client_2.12 | 0.23.35 | GHSA-grh8-3p95-f9rr |
| Maven | org.http4s:http4s-client_2.13 | 0.23.35 | GHSA-grh8-3p95-f9rr |
| Maven | org.http4s:http4s-client_2.13 | 1.0.0-M47 | GHSA-grh8-3p95-f9rr |
| Maven | org.http4s:http4s-client_3 | 0.23.35 | GHSA-grh8-3p95-f9rr |
| Maven | org.http4s:http4s-client_3 | 1.0.0-M47 | GHSA-grh8-3p95-f9rr |
Affected products (as reported)
Weakness: CWE-565, CWE-1275 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N
References
- https://github.com/http4s/http4s/security/advisories/GHSA-grh8-3p95-f9rr x_refsource_CONFIRM
- https://github.com/http4s/http4s/commit/c0a37f38d5ee2a568ba57bd9da62f8d79b8b1fcc x_refsource_MISC
- https://github.com/http4s/http4s/releases/tag/v0.23.35 x_refsource_MISC
- https://github.com/http4s/http4s/releases/tag/v1.0.0-M47 x_refsource_MISC