6.9 Medium

CVE-2026-119131 Wasmtime 46.0.0 before 48.0.6 and 49.0.0 before 49.0.3 Host Panic via wasi-http

Description

Wasmtime 46.0.0 before 48.0.6 and 49.0.0 before 49.0.3 contains a denial of service vulnerability in wasmtime-wasi-http that lets guests crash the host by sending long request URLs. Guests can use set-path-with-query with a '?' after byte 65535, overflowing a u16 index in the http crate and triggering a host panic.

CVSS 4.0 detail

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

Exploitable remotely over the network, without an account and without any user action; the impact on data or service is limited.

Attack vector: Network
Attack complexity: Low
Attack requirements: None
Privileges required: None
Interaction: None
Confidentiality: None
Integrity: None
Availability: Low
Confidentiality of other systems: None
Integrity of other systems: None
Availability of other systems: None

Affected products and versions

Product	Affected versions	Fixed in
wasmtime 49.0	49.0.0 → < 49.0.3	49.0.3
wasmtime 48.0	earliest → < 48.0.6	48.0.6
wasmtime 46.0	46.0.0 → < 48.0.6	48.0.6

References

GitHub Security Advisory (GHSA-w36r-2hch-9xp9) github.com
VulnCheck Advisory: Wasmtime 46.0.0 before 48.0.6 and 49.0.0 before 49.0.3 Host Panic via wasi-http www.vulncheck.com

Timeline

Published October 29, 2026
Last modified November 4, 2026

The 81 CVEs of wasmtime →

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