Quick answers
- Is CVE-2026-118688 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-118688 being exploited in the wild.
- How severe is CVE-2026-118688?
- High severity, with a CVSS score of 7.9, published 28 October 2026.
- Which products and versions are affected?
- Bytecode Alliance Wasmtime <36.0.18, >=37.0.0 <48.0.6, >=49.0.0 <49.0.3.
- Is there a fix for CVE-2026-118688?
- Yes: fixed in 36.0.18, 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-2026-118688 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-118688?
- 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: 36.0.18, 48.0.6, 49.0.3
Technical details
The wasmtime-wasi crate strips trailing slashes from rename source paths but re-appends them before calling renameat, allowing symlinks to be followed on macOS and FreeBSD. A guest can create a relative symlink pointing outside the sandbox (e.g., symlink("../outside", "up")) and rename "up/" to move external directories into its sandbox. This affects wasmtime-wasi versions before 36.0.18, 37.0.0–48.0.5, and 49.0.0–49.0.2; Linux and Windows are not affected due to their renameat behavior.
Affected products
- Bytecode Alliance Wasmtime <36.0.18, >=37.0.0 <48.0.6, >=49.0.0 <49.0.3
Timeline
- 2026-10-14: disclosed
- 2026-10-28: advisory