Quick answers
- Is CVE-2026-119140 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-119140 being exploited in the wild.
- How severe is CVE-2026-119140?
- Medium severity, with a CVSS score of 4.8, published 29 October 2026.
- Which products and versions are affected?
- Bytecode Alliance Wasmtime 46.0.0 to 48.0.5; 49.0.0 to 49.0.2.
- Is there a fix for CVE-2026-119140?
- Yes: fixed in Wasmtime 48.0.6, 49.0.3. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-119140 attacked?
- It is attacked over the network.
- Am I affected by CVE-2026-119140?
- Check whether you run Bytecode Alliance Wasmtime at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- Fixed in: Wasmtime 48.0.6, 49.0.3
Technical details
The vulnerability occurs when a component start function calls an async-lowered import followed by thread.yield, causing the runtime to mistrack thread state and drop an undisposed fiber, which panics during cleanup. The vulnerability affects versions 46.0.0–48.0.5 and 49.0.0–49.0.2. Exploitation requires the ability to supply a malicious WebAssembly component to an embedder.
Affected products
- Bytecode Alliance Wasmtime 46.0.0 to 48.0.5; 49.0.0 to 49.0.2
Timeline
- 2026-10-14: disclosed
- 2026-10-29: advisory