CVE-2026-69216
Http4s: Ember chunk parser lenience (TE.TE request smuggling)
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
Description
Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, Ember’s chunk decoder trims the chunk-size token and accepts leading plus or minus signs instead of requiring one or more hexadecimal digits followed by the required CRLF. When an intermediary forwards chunked data without re-encoding and interprets malformed chunk boundaries differently, an unauthenticated attacker can create TE.TE request smuggling that bypasses intermediary controls, poisons caches, or hijacks the request queue. The same response-path leniency can enable response smuggling against an ember-client used as a gateway when the upstream is malicious or compromised. This issue is fixed in versions 0.23.35 and 1.0.0-M47.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Medium5.4 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N |
| NVDNVD · Deferred | 3.1 | Medium5.4 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N |
- EPSS (exploitation in 30 days)
- 0.37% · top 69% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.4.
Weakness
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Mavenorg.http4s:http4s-ember-core_2.12GHSA-jrpm-956j-96jg (opens in a new tab)
- Mavenorg.http4s:http4s-ember-core_2.13GHSA-jrpm-956j-96jg (opens in a new tab)
- Mavenorg.http4s:http4s-ember-core_3GHSA-jrpm-956j-96jg (opens in a new tab)
References (4)
- https://github.com/http4s/http4s/security/advisories/GHSA-jrpm-956j-96jg (opens in a new tab)x_refsource_CONFIRM
- https://github.com/http4s/http4s/commit/d78612a5abd5a2547487598d3342be05573e16f0 (opens in a new tab)x_refsource_MISC
- https://github.com/http4s/http4s/releases/tag/v0.23.35 (opens in a new tab)x_refsource_MISC
- https://github.com/http4s/http4s/releases/tag/v1.0.0-M47 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-jrpm-956j-96jg (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-69216)Record last updated .