CVE-2026-115889

Name	CVE-2026-115889
Description	Wasmtime is a runtime for WebAssembly. Prior to 36.0.19 and 43.0.0, the Cranelift compiler backend bit-packs SSA value indices in a way that can silently overflow in release builds when compiling a sufficiently large or specially crafted Wasm function with many SSA values. The overflow can make Cranelift reference incorrect IR values, causing arbitrary miscompilation, type confusion, and other attacker-controlled effects that may escape the Wasm sandbox on any architecture using the default Cranelift backend. This issue is fixed in versions 36.0.19 and 43.0.0.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs	1151861

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
rust-wasmtime (PTS)	trixie	26.0.1+dfsg-3	vulnerable
	forky, sid	36.0.20+dfsg-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
rust-wasmtime	source	(unstable)	36.0.20+dfsg-1			1151861

Notes

https://rustsec.org/advisories/RUSTSEC-2026-0380.html
https://github.com/advisories/GHSA-897f-g5gm-fmxm
https://github.com/bytecodealliance/wasmtime/pull/12613