Severity by source
AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N
Primary rating from Vendor (GitHub_M) · only source for this CVE.
CVSS VectorVendor: GitHub_M
Lifecycle Timeline
5Blast Radius
ecosystem impact- 3 maven packages depend on org.http4s:http4s-ember-core_2.12 (2 direct, 1 indirect)
Ecosystem-wide dependent count for version 0.23.35.
DescriptionCVE.org
Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, Ember’s HeaderP.parse uses a case-sensitive substring test for the Transfer-Encoding value and decodes header bytes with the platform default charset. Values such as Chunked are not recognized, values such as notchunked are incorrectly accepted, and Unicode case folding can turn a Kelvin-sign byte sequence into a match when UTF-8 is used. Intermediaries that apply RFC-compliant token and charset rules can therefore disagree with Ember’s Content-Length or zero-length framing, enabling TE.CL or TE.0 request smuggling, access-control bypass, cross-user request hijacking, and cache poisoning on the server path. Response smuggling through an ember-client gateway requires a malicious or compromised upstream. This issue is fixed in versions 0.23.35 and 1.0.0-M47.
AnalysisAI
Let me synthesize. CVE-2026-69205: http4s Ember HTTP parser request smuggling via Transfer-Encoding header case-sensitivity and charset decoding issues. …
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Same weakness CWE-444 – HTTP Request/Response Smuggling
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External POC / Exploit Code
Leaving vuln.today
EUVD-2026-79190
GHSA-9998-894r-fwvr