Not a U.S. government website. NDD is an independent vulnerability database by Volerion and is not affiliated with or endorsed by NIST or NVD.

CVE-2026-121439 Details

ANALYZED

This CVE record has been analyzed and enriched by NVDAPI.com as an independent party.

Description

Wasmtime 46.0.0 before 48.0.7 and 49.0.0 before 49.0.4 contains a response splitting vulnerability in wasi-http p3 that allows guests to set unvalidated content-length headers. Malicious wasip3 guests can splice an existing body into a new response with an incorrect content-length to perform response splitting or injection attacks.

Metrics

CVSS 3.x Severity and Vector Strings:

VolerionCVSS-B:4.3 MEDIUMVector:CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

CNA: [email protected]CVSS-B:5.3 MEDIUMVector:CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

References to Advisories, Solutions, and Tools

By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.

URL	Source(s)	Tag(s)
https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-9prg-84vf-g5fc	[email protected]	AdvisoryRemedyVendor
https://www.vulncheck.com/advisories/wasmtime-46.0.0-before-48.0.7-and-49.0.0-before-49.0.4-http-response-splitting-via-wasi-http	[email protected]	Advisory

Weakness Enumeration

CWE-ID	CWE Name	Source
CWE-444	Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')	[email protected]

Affected Products

Product	Versions
Bytecode Alliance Wasmtime	>= 46.0.0, < 48.0.7 (semver) >= 49.0.0, < 49.0.4 (semver)
CPE cpe:2.3:a:bytecodealliance:wasmtime::::::rust::* Remediation Upgrade: 48.0.7moderate effort Upgrade: 49.0.4moderate effort

Change History

1 change record found show changes