GHSA-96f6-r43r-8c24: wasmtime-wasi (CVE-2026-115386)

fd_readdir copies uninitialized struct padding into guest memory

CVSS 2.1 LowEPSS 0.0020 · 9th percentile

Published by the GitHub Advisory Database at 2 Oct 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-wasi	crates.io	>=0.0.0-0, <36.0.17 \|\| >=37.0.0, <48.0.4 \|\| >=49.0.0, <49.0.2	36.0.17, 48.0.4, 49.0.2

Identifiers

GHSA-96f6-r43r-8c24 · CVE-2026-115386 · RUSTSEC-2026-0323

Weakness (CWE)

CWE-908

Machine-written summary

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

The wasmtime-wasi crate has a flaw in its fd_readdir implementation: it copies uninitialized struct padding into guest memory. The source gives few details beyond this, so it is not clear what a guest module would need to trigger it or what exactly it could read. Upgrade wasmtime-wasi to 36.0.17, 48.0.4, 49.0.2, or a later fixed release.

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
2.1	Low	4.0	CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N	CNA (VulnCheck)

CISA KEV Not listed.
EPSS 0.0020, the 9th 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.