CVE-2026-121441

    Dashboard / Vulnerabilities / CVE-2026-121441

    CVE-2026-121441

    Published: 3 Nov 2026Last Modified: 5 Nov 2026

    Summary: Wasmtime before 36.0.19, 37.0.0 before 48.0.7, and 49.0.0 before 49.0.4 wasi-http Request Smuggling

    Details: Wasmtime before 36.0.19, 37.0.0 before 48.0.7, and 49.0.0 before 49.0.4 contains a request smuggling vulnerability in wasi-http that allows guests to set multiple conflicting content-length headers. Malicious guests can make the host send HTTP requests with conflicting content-length values to smuggle requests through servers or intermediaries that do not reject them.

    References: https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/121xxx/CVE-2026-121441.json, https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-r8xh-cgf7-392j, https://nvd.nist.gov/vuln/detail/CVE-2026-121441, https://www.vulncheck.com/advisories/wasmtime-before-36.0.19-37.0.0-before-48.0.7-and-49.0.0-before-49.0.4-wasi-http-request-smuggling

    Affected packages

    Package

    Name:

    Purl:

    Affected ranges

    Type: GIT

    Events:

    Introduced- 0
    Fixed -0d6b8ead4e94b0ce76f925611b831b56570aef94

    Affected versions

    v36.0.18
    v36.0.17
    v36.0.16
    v36.0.15
    v36.0.14
    v36.0.13
    v36.0.12
    v36.0.11
    v36.0.10
    v36.0.9
    v36.0.8
    v36.0.7
    v36.0.6
    v36.0.5
    v36.0.4
    v36.0.3
    v36.0.2
    v36.0.1
    v36.0.0

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    CVE-2026-121441 | CVE-DB