CVE-2026-34945 Wasmtime leaks host data with 64-bit tables and Winch
LowCVSS 2.3
EPSS 0.34%
- Published
- Updated
- Exploit status
- No public exploit known
Description
Wasmtime is a runtime for WebAssembly. From 25.0.0 to before 36.0.7, 42.0.2, and 43.0.1, Wasmtime's Winch compiler contains a bug where a 64-bit table, part of the memory64 proposal of WebAssembly, incorrectly translated the table.size instruction. This bug could lead to disclosing data on the host's stack to WebAssembly guests. The host's stack can possibly contain sensitive data related to other host-originating operations which is not intended to be disclosed to guests. This bug specifically arose from a mistake where the return value of table.size was statically typed as a 32-bit integer, as opposed to consulting the table's index type to see how large the returned register could be. When combined with details about Wnich's ABI, such as multi-value returns, this can be combined to read stack data from the host, within a guest. This vulnerability is fixed in 36.0.7, 42.0.2, and 43.0.1.
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| bytecodealliance wasmtime | = >= 25.0.0, < 36.0.7 | No fix listed |
| bytecodealliance wasmtime | = >= 37.0.0, < 42.0.2 | No fix listed |
| bytecodealliance wasmtime | = >= 43.0.0, < 44.0.1 | No fix listed |
| crates.io wasmtime(crates.io) | >= 25.0.0, < 36.0.7 | 36.0.7 |
| crates.io wasmtime(crates.io) | >= 37.0.0, < 42.0.2 | 42.0.2 |
| crates.io wasmtime(crates.io) | >= 43.0.0, < 43.0.1 | 43.0.1 |
| crates.io wasmtime(crates.io) | = 43.0.0 | No fix listed |
| crates.io wasmtime(crates.io) | >= 0.0.0-0, < 36.0.7 | 36.0.7 |
| debian/rust-wasmtime(Debian:13) | All versions | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 26.0.1+dfsg-10 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 26.0.1+dfsg-3 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 26.0.1+dfsg-4 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 26.0.1+dfsg-5 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 26.0.1+dfsg-6 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 26.0.1+dfsg-7 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 26.0.1+dfsg-8 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 26.0.1+dfsg-9 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 27.0.0+dfsg-2 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 27.0.0+dfsg-3 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 27.0.0+dfsg-4 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 28.0.1+dfsg-1 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 28.0.1+dfsg-2 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 28.0.1+dfsg-3 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 29.0.1+dfsg-1 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 29.0.1+dfsg-2 | No fix listed |
Show 70 more
| Product | Affected versions | Fixed in |
|---|---|---|
| debian/rust-wasmtime(Debian:13) | = 29.0.1+dfsg-3 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 29.0.1+dfsg-4 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 29.0.1+dfsg-5 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 29.0.1+dfsg-6 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 29.0.1+dfsg-7 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 29.0.1+dfsg-8 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 36.0.11+dfsg-1 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 36.0.12+dfsg-1 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 36.0.12+dfsg-2 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 36.0.12+dfsg-3 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 36.0.13+dfsg-1 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 36.0.5+dfsg-1 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 36.0.5+dfsg-2 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 36.0.5+dfsg-3 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 36.0.5+dfsg-4 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 36.0.5+dfsg-5 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 36.0.6+dfsg-1 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 36.0.6+dfsg-2 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 36.0.6+dfsg-3 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 36.0.6+dfsg-4 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 36.0.6+dfsg-5 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 36.0.6+dfsg-6 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 36.0.6+dfsg-7 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 36.0.7+dfsg-1 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 36.0.8+dfsg-1 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 36.0.9+dfsg-1 | No fix listed |
| debian/rust-wasmtime(Debian:13) | = 36.0.9+dfsg-2 | No fix listed |
| debian/rust-wasmtime(Debian:14) | < 36.0.7+dfsg-1 | 36.0.7+dfsg-1 |
| debian/rust-wasmtime(Debian:14) | = 26.0.1+dfsg-10 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 26.0.1+dfsg-3 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 26.0.1+dfsg-4 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 26.0.1+dfsg-5 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 26.0.1+dfsg-6 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 26.0.1+dfsg-7 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 26.0.1+dfsg-8 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 26.0.1+dfsg-9 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 27.0.0+dfsg-2 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 27.0.0+dfsg-3 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 27.0.0+dfsg-4 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 28.0.1+dfsg-1 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 28.0.1+dfsg-2 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 28.0.1+dfsg-3 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 29.0.1+dfsg-1 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 29.0.1+dfsg-2 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 29.0.1+dfsg-3 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 29.0.1+dfsg-4 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 29.0.1+dfsg-5 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 29.0.1+dfsg-6 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 29.0.1+dfsg-7 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 29.0.1+dfsg-8 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 36.0.5+dfsg-1 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 36.0.5+dfsg-2 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 36.0.5+dfsg-3 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 36.0.5+dfsg-4 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 36.0.5+dfsg-5 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 36.0.6+dfsg-1 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 36.0.6+dfsg-2 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 36.0.6+dfsg-3 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 36.0.6+dfsg-4 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 36.0.6+dfsg-5 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 36.0.6+dfsg-6 | No fix listed |
| debian/rust-wasmtime(Debian:14) | = 36.0.6+dfsg-7 | No fix listed |
| redhat/redhat-user-workloads/rhcl-1-3-wasm-shim(Red Hat:connectivity_link:1) | All versions | No fix listed |
| redhat/virt-firmware-rs(Red Hat:enterprise_linux:10) | All versions | No fix listed |
| ubuntu/rust-wasmtime(Ubuntu:24.04) | All versions | No fix listed |
| ubuntu/rust-wasmtime(Ubuntu:26.04) | All versions | No fix listed |
| ubuntu/rust-wasmtime(Ubuntu:26.10) | All versions | No fix listed |
| bytecodealliance wasmtime | >= 25.0.0, < 36.0.7 | 36.0.7 |
| bytecodealliance wasmtime | >= 37.0.0, < 42.0.2 | 42.0.2 |
| bytecodealliance wasmtime | >= 43.0.0, < 43.0.1 | 43.0.1 |
References
- https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-m9w2-8782-2946 vendor-advisory
- nvd.nist.gov third-party-advisory vendor-advisory
- github.com product
- rustsec.org vendor-advisory
- crates.io product
- github.com
- github.com
- Debian Security Tracker CVE-2026-34945 vendor-advisory
- Red Hat CVE page mitigation vendor-advisory
- Red Hat Bugzilla 2457004 issue-tracking
- www.cve.org
- Ubuntu CVE tracker vendor-advisory
- bugs.debian.org issue-tracking