# CVE-2025-59822: Http4s vulnerable to HTTP Request Smuggling due to improper handling of HTTP trailer section

Source: https://junglewise.ai/threats/cve-2025-59822-http4s-vulnerable-to-http-request-smuggling-due-to-improper  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2025-09-23  
License: CC BY 4.0 with a link back

CVE-2025-59822 · Severity: medium · CVSS 4 · Published 2025-09-23

Http4s vulnerable to HTTP Request Smuggling due to improper handling of HTTP trailer section

Technologies: [org.http4s:http4s-ember-core_2.12 (Maven)](https://junglewise.ai/threats/technologies/org-http4s-http4s-ember-core-2-12), [org.http4s:http4s-ember-core_2.13 (Maven)](https://junglewise.ai/threats/technologies/org-http4s-http4s-ember-core-2-13), [org.http4s:http4s-ember-core_3 (Maven)](https://junglewise.ai/threats/technologies/org-http4s-http4s-ember-core-3). Vendors: [Maven](https://junglewise.ai/threats/vendors/maven).

## Quick answers

**Is CVE-2025-59822 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2025-59822 being exploited in the wild.

**How severe is CVE-2025-59822?** Medium severity, with a CVSS score of 4, published 23 September 2025.

**Which products and versions are affected?** org.http4s:http4s-ember-core_2.12 (Maven) ECOSYSTEM:introduced=0,fixed=0.23.31; org.http4s:http4s-ember-core_2.13 (Maven) ECOSYSTEM:introduced=0,fixed=0.23.31; org.http4s:http4s-ember-core_3 (Maven) ECOSYSTEM:introduced=0,fixed=0.23.31.

**Is there a fix for CVE-2025-59822?** Yes. org.http4s:http4s-ember-core_2.12 (Maven): upgrade to 0.23.31 or later; org.http4s:http4s-ember-core_2.13 (Maven): upgrade to 0.23.31 or later; org.http4s:http4s-ember-core_3 (Maven): upgrade to 0.23.31 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2025-59822?** Check whether you run org.http4s:http4s-ember-core_2.12 (Maven), org.http4s:http4s-ember-core_2.13 (Maven) or org.http4s:http4s-ember-core_3 (Maven) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- org.http4s:http4s-ember-core_2.12 (Maven): upgrade to 0.23.31 or later

  ```sh
  # set org.http4s:http4s-ember-core_2.12 to 0.23.31 in your pom.xml or build.gradle
  ```

- org.http4s:http4s-ember-core_2.13 (Maven): upgrade to 0.23.31 or later

  ```sh
  # set org.http4s:http4s-ember-core_2.13 to 0.23.31 in your pom.xml or build.gradle
  ```

- org.http4s:http4s-ember-core_3 (Maven): upgrade to 0.23.31 or later

  ```sh
  # set org.http4s:http4s-ember-core_3 to 0.23.31 in your pom.xml or build.gradle
  ```


## Affected products

- org.http4s:http4s-ember-core_2.12 (Maven) ECOSYSTEM:introduced=0,fixed=0.23.31
- org.http4s:http4s-ember-core_2.13 (Maven) ECOSYSTEM:introduced=0,fixed=0.23.31
- org.http4s:http4s-ember-core_3 (Maven) ECOSYSTEM:introduced=0,fixed=0.23.31

## Identifiers

- CVE-2025-59822
- GHSA-wcwh-7gfw-5wrr

## Related threats

- [Http4s Ember HTTP/2 frame buffering denial of service](https://junglewise.ai/threats/cve-2026-88975-http4s-ember-http-2-frame-buffering-denial-of-service)
- [Http4s Ember HTTP/2 unbounded continuation frame accumulation](https://junglewise.ai/threats/cve-2026-69218-http4s-ember-http-2-unbounded-continuation-frame-accumulation)
- [Http4s DigestAuth replay attack in authorization header](https://junglewise.ai/threats/cve-2026-69206-http4s-digestauth-replay-attack-in-authorization-header)
- [Http4s Ember HTTP request smuggling via Transfer-Encoding parsing](https://junglewise.ai/threats/cve-2026-69205-http4s-ember-http-request-smuggling-via-transfer-encoding-parsing)
- [Http4s Ember HTTP/2 stream limit enforcement bypass](https://junglewise.ai/threats/cve-2026-69203-http4s-ember-http-2-stream-limit-enforcement-bypass)