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6.9 Medium

CVE-2026-121439 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…

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.

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 46.0 46.0.0 → < 48.0.7 48.0.7
The 81 CVEs of wasmtime →
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