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6.3 Medium

CVE-2026-121441 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…

Description

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 products and versions

Product Affected versions Fixed in
wasmtime 49.0 49.0.0 → < 49.0.4 49.0.4
wasmtime 48.0 earliest → < 48.0.7 48.0.7
wasmtime 37.0 37.0.0 → < 48.0.7 48.0.7
wasmtime 36.0 earliest → < 36.0.19 36.0.19
The 81 CVEs of wasmtime →
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