GHSA-qqfj-4vcm-26hv: wasmtime (CVE-2026-34944)

Wasmtime segfault or unused out-of-sandbox load with `f64x2.splat` operator on Cranelift x86-64

CVSS 4.1 MediumEPSS 0.0024 · 14th percentile

Published by the GitHub Advisory Database at 9 Apr 2026, 12:00 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

Package	Ecosystem	Affected	Fixed in
wasmtime	crates.io	>=0.0.0-0, <24.0.7 \|\| >=25.0.0, <36.0.7 \|\| >=37.0.0, <42.0.2 \|\| >=43.0.0, <43.0.1	24.0.7, 36.0.7, 42.0.2, 43.0.1

Identifiers

GHSA-qqfj-4vcm-26hv · CVE-2026-34944 · RUSTSEC-2026-0087

Weakness (CWE)

CWE-248

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

Wasmtime versions before 24.0.7, from 25.0.0 before 36.0.7, from 37.0.0 before 42.0.2, and from 43.0.0 before 43.0.1 are affected. The source gives few details: it describes a segfault or unused out-of-sandbox load involving the f64x2.splat operator on Cranelift for x86-64. Upgrade to 24.0.7, 36.0.7, 42.0.2, 43.0.1 or later.

Written 3 Nov 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
4.1	Medium	4.0	CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N	CNA (GitHub_M)

CISA KEV Not listed.
EPSS 0.0024, the 14th percentile, on 7 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

31 Oct 2026, 14:24 UTC First seen by agentprime
31 Oct 2026, 14:24 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.