# CVE-2026-69203

## Summary

- **CVE ID:** CVE-2026-69203
- **Severity:** HIGH
- **CVSS Score:** 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
- **CWE:** CWE-400, CWE-770
- **Published:** Sep 15, 2026
- **Last Modified:** Sep 15, 2026

## Description

Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, An Ember server with HTTP/2 enabled through withHttp2 does not enforce SETTINGS_MAX_CONCURRENT_STREAMS for peer-created streams. One unauthenticated connection can open an unbounded number of streams, each retaining per-stream state until heap exhaustion. The same unchecked allocation is reachable in an ember-client through server-initiated PUSH_PROMISE frames because enablePush is not enforced. This issue is fixed in versions 0.23.35 and 1.0.0-M47.

## Affected Products

- http4s — http4s (< 0.23.35)
- http4s — http4s (>= 1.0.0-M1, < 1.0.0-M47)

## References

- [CNA](https://github.com/http4s/http4s/security/advisories/GHSA-9vwc-pc8p-253q)
- [CNA](https://github.com/http4s/http4s/commit/4983de1f93f2caaa3b9de310cf6a9db32c50d66e)
- [CNA](https://github.com/http4s/http4s/releases/tag/v0.23.35)
- [CNA](https://github.com/http4s/http4s/releases/tag/v1.0.0-M47)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.46%
- **EPSS Percentile:** 38.9

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-17._