CVE-2026-121441
Low · 3.7CVSS
3.7
EPSS
0.2%
Published
Nov 3, 2026
CISA due date
—
The record
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.
Affected packages
| Ecosystem | Package | Introduced | Fixed |
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Related vulnerabilities
- CVE-2026-121439 Wasmtime 46.0.0 before 48.0.7 and 49.0.0 before 49.0.4 contains a response splitting… CWE-444
- CVE-2026-55613 uhttpd is a small HTTP server. CWE-444
- CVE-2026-55614 uhttpd is a small HTTP server. CWE-444
- CVE-2026-55612 uhttpd is a small HTTP server. CWE-444
- CVE-2026-116127 Starlet versions before 0.33 for Perl send a body in responses to HEAD requests… CWE-444
- CVE-2026-91920 A flaw was found in the ChunkReader component of the Undertow web server, which is used… CWE-444
- CVE-2026-118264 Echo is a Go web framework. CWE-444
- CVE-2026-103995 Response body and chunk parsing would handle non-hex or negative integers incorrectly… CWE-444