CVE-2026-119143 Wasmtime 46.0.0 before 48.0.6 and 49.0.0 before 49.0.3 Panic via Zero-Length Stream Writes
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-119143?
CVE-2026-119143 is a medium-severity vulnerability in bytecodealliance wasmtime, published on 29 Oct 2026.
Official description
Wasmtime 46.0.0 before 48.0.6 and 49.0.0 before 49.0.3 contains a denial of service vulnerability that allows guest code to trigger a host panic through out-of-bounds zero-length stream operations. Malicious guests can perform zero-length component model stream reads or writes with unvalidated addresses, causing Direct{Source,Destination}::remaining to panic and crash WASIp3 embedders.
Weakness: CWE-129
Which versions are affected by CVE-2026-119143?
1 open source package ship an affected version, including wasmtime.
| Package | Affected | Fixed in |
|---|---|---|
wasmtime crates.io | From 46.0.0 | 48.0.6, 49.0.3 |
How do I fix CVE-2026-119143?
Upgrade wasmtime to a fixed version for your release line: 48.0.6 or 49.0.3.
Is CVE-2026-119143 being exploited?
There is no known exploitation of CVE-2026-119143 in the wild and no public exploit code.
Sources
Also known as GHSA-368p-492j-h227, GHSA-93g3-36p8-x2gc, RUSTSEC-2026-0357.