# Http4s vulnerabilities

Source: https://junglewise.ai/threats/technologies/http4s  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Updated: 9 November 2026, 03:07 UTC. Rebuilt every hour.  
Data: https://junglewise.ai/threats/technologies/http4s.json  
License: CC BY 4.0 with a link back

Junglewise Threat Intelligence has tracked 6 vulnerabilities in Http4s: 0 in the last 7 days and 6 in the last 90 days, 0 of them critical and 0 exploited in the wild. The most recent, CVE-2026-69217, was published on 15 September 2026. Nothing in the last four weeks, down from 6 vulnerabilities in the four before.

## Counts

- Last 7 days: 0
- Last 30 days: 0
- Last 90 days: 6
- All time: 6 (0 critical, 0 exploited in the wild)

## About Http4s

Scala functional HTTP library providing composable and type-safe HTTP client/server tools.

## Latest Http4s vulnerabilities

- [CVE-2026-69217: Http4s Ember HTTP/1.1 parser request smuggling via duplicate Content-Length](https://junglewise.ai/threats/cve-2026-69217-http4s-ember-http-1-1-parser-request-smuggling-via-duplicate) (high, CVSS 8.7, published 15 Sep 2026)
- [CVE-2026-69210: Http4s WebSocket decoder negative length handling denial of service](https://junglewise.ai/threats/cve-2026-69210-http4s-websocket-decoder-negative-length-handling-denial-of) (high, CVSS 7.5, published 15 Sep 2026)
- [CVE-2026-69206: Http4s DigestAuth replay attack in authorization header](https://junglewise.ai/threats/cve-2026-69206-http4s-digestauth-replay-attack-in-authorization-header) (medium, CVSS 5.9, published 15 Sep 2026)
- [CVE-2026-69212: Http4s FollowRedirect credential leak on scheme downgrade](https://junglewise.ai/threats/cve-2026-69212-http4s-followredirect-credential-leak-on-scheme-downgrade) (medium, CVSS 5.9, published 15 Sep 2026)
- [CVE-2026-69211: Http4s ResponseCookie header injection via unescaped attributes](https://junglewise.ai/threats/cve-2026-69211-http4s-responsecookie-header-injection-via-unescaped-attributes) (medium, CVSS 4.8, published 15 Sep 2026)
- [CVE-2026-69201: Http4s ResourceService and WebjarService path traversal via percent-encoded separators](https://junglewise.ai/threats/cve-2026-69201-http4s-resourceservice-and-webjarservice-path-traversal-via) (medium, CVSS 5.9, published 15 Sep 2026)

## Most severe Http4s vulnerabilities

- [CVE-2026-69217: Http4s Ember HTTP/1.1 parser request smuggling via duplicate Content-Length](https://junglewise.ai/threats/cve-2026-69217-http4s-ember-http-1-1-parser-request-smuggling-via-duplicate) (high, CVSS 8.7, published 15 Sep 2026)
- [CVE-2026-69210: Http4s WebSocket decoder negative length handling denial of service](https://junglewise.ai/threats/cve-2026-69210-http4s-websocket-decoder-negative-length-handling-denial-of) (high, CVSS 7.5, published 15 Sep 2026)
- [CVE-2026-69201: Http4s ResourceService and WebjarService path traversal via percent-encoded separators](https://junglewise.ai/threats/cve-2026-69201-http4s-resourceservice-and-webjarservice-path-traversal-via) (medium, CVSS 5.9, published 15 Sep 2026)
- [CVE-2026-69206: Http4s DigestAuth replay attack in authorization header](https://junglewise.ai/threats/cve-2026-69206-http4s-digestauth-replay-attack-in-authorization-header) (medium, CVSS 5.9, published 15 Sep 2026)
- [CVE-2026-69212: Http4s FollowRedirect credential leak on scheme downgrade](https://junglewise.ai/threats/cve-2026-69212-http4s-followredirect-credential-leak-on-scheme-downgrade) (medium, CVSS 5.9, published 15 Sep 2026)
- [CVE-2026-69211: Http4s ResponseCookie header injection via unescaped attributes](https://junglewise.ai/threats/cve-2026-69211-http4s-responsecookie-header-injection-via-unescaped-attributes) (medium, CVSS 4.8, published 15 Sep 2026)

## Vulnerabilities per week

Nothing in the last four weeks, down from 6 vulnerabilities in the four before.

| Week of | Vulns | Critical | Exploited |
| --- | --- | --- | --- |
| 17 Aug 2026 | 0 | 0 | 0 |
| 24 Aug 2026 | 0 | 0 | 0 |
| 31 Aug 2026 | 0 | 0 | 0 |
| 7 Sep 2026 | 0 | 0 | 0 |
| 14 Sep 2026 | 6 | 0 | 0 |
| 21 Sep 2026 | 0 | 0 | 0 |
| 28 Sep 2026 | 0 | 0 | 0 |
| 5 Oct 2026 | 0 | 0 | 0 |
| 12 Oct 2026 | 0 | 0 | 0 |
| 19 Oct 2026 | 0 | 0 | 0 |
| 26 Oct 2026 | 0 | 0 | 0 |
| 2 Nov 2026 | 0 | 0 | 0 |
| 9 Nov 2026 | 0 | 0 | 0 |

## Other Http4s technologies

- [Http4s-Ember-Core](https://junglewise.ai/threats/technologies/http4s-ember-core): 10 vulnerabilities

## Sources

NVD, GitHub Security Advisories, OSV, the CISA Known Exploited Vulnerabilities catalog, FIRST EPSS and vendor advisories. Rebuilt every hour. Cite as: Junglewise Threat Intelligence, "Http4s vulnerabilities", https://junglewise.ai/threats/technologies/http4s, 9 November 2026.