CVE-2026-69204

Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, Ember HTTP/1.1 does not reject messages containing both Transfer-Encoding and Content-Length, so an intermediary and Ember can select different body framing rules. When ember-server is behind a keep-alive intermediary that forwards both headers and frames by Content-Length, an unauthenticated attacker can smuggle a second request, bypass intermediary access controls, poison caches, or cause a victim request to be joined to an attacker-controlled prefix. The shared response parser can also desynchronize an ember-client connection when a malicious or compromised upstream sends both headers. This issue is fixed in versions 0.23.35 and 1.0.0-M47.

CVSS

No CVSS.

References

Link	Resource
https://github.com/http4s/http4s/commit/9feaf8677951a52af906ae9664ff6f0543d9d810
https://github.com/http4s/http4s/releases/tag/v0.23.35
https://github.com/http4s/http4s/releases/tag/v1.0.0-M47
https://github.com/http4s/http4s/security/advisories/GHSA-8h4c-x2wg-6xp8

Configurations

No configuration.

History

No history.

Information

Published : 2026-09-15 19:17

Updated : 2026-09-15 19:17

NVD link : CVE-2026-69204

Mitre link : CVE-2026-69204

CVE.ORG link : CVE-2026-69204

JSON object : View

Products Affected

No product.

CWE

CWE-444

Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

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