# Http4s: Ember chunk parser lenience (TE.TE request smuggling)

Advisory record · `GHSA-jrpm-956j-96jg`

- **Identifiers:** `GHSA-jrpm-956j-96jg` · `CVE-2026-69216`
- **State:** Confirmed
- **Severity:** CVSS 5.4 Medium
- **Critical:** No
- **Weakness (CWE):** [CWE-444](https://cwe.mitre.org/data/definitions/444.html)
- **Tags:** [HTTP request smuggling](https://agentprime.io/advisories/tag/request-smuggling.md)
- **Published:** 15 Sept 2026
- **Updated:** 15 Sept 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 15 Sept 2026, 20:01 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `org.http4s:http4s-ember-core_2.12` (Maven): affected `<0.23.35`; fixed in `0.23.35`
- `org.http4s:http4s-ember-core_2.13` (Maven): affected `<0.23.35 || >=1.0.0-M1, <1.0.0-M47`; fixed in `0.23.35`, `1.0.0-M47`
- `org.http4s:http4s-ember-core_3` (Maven): affected `<0.23.35 || >=1.0.0-M1, <1.0.0-M47`; fixed in `0.23.35`, `1.0.0-M47`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> Affected are the http4s-ember-core packages for Scala 2.12, 2.13 and 3 (Maven org.http4s), with versions below 0.23.35 and, for 2.13 and 3, versions from 1.0.0-M1 up to but not including 1.0.0-M47. Upgrade to 0.23.35 or 1.0.0-M47 as applicable. An unauthenticated remote attacker can send chunked requests with malformed chunk sizes that an intermediary parses differently, enabling request smuggling when ember-server sits behind a keep-alive proxy. The source describes a workaround: configure the intermediary to reject malformed chunk sizes or to re-encode request bodies.

Written 2 Nov 2026.

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 5.4 Medium, CVSS 3.1: `CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0037, the 30th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:16 UTC: First seen by agentprime
- 31 Oct 2026, 14:16 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-jrpm-956j-96jg)

## Sources

- [GitHub Advisory Database: GHSA-jrpm-956j-96jg](https://github.com/advisories/GHSA-jrpm-956j-96jg)
- [OSV: GHSA-jrpm-956j-96jg](https://osv.dev/vulnerability/GHSA-jrpm-956j-96jg)
- <https://github.com/http4s/http4s/security/advisories/GHSA-jrpm-956j-96jg>
- <https://github.com/http4s/http4s/commit/d78612a5abd5a2547487598d3342be05573e16f0>
- <https://github.com/http4s/http4s>
- <https://github.com/http4s/http4s/releases/tag/v0.23.35>
- <https://github.com/http4s/http4s/releases/tag/v1.0.0-M47>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-jrpm-956j-96jg>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-jrpm-956j-96jg/>. Everything for agents: <https://agentprime.io/llms.txt>.
