CVE-2022-39394 — Wasmtime is a standalone runtime for WebAssembly

Wasmtime is a standalone runtime for WebAssembly. Prior to version 2.0.2, there is a bug in Wasmtime's C API implementation where the definition of the `wasmtime_trap_code` does not match its declared signature in the `wasmtime/trap.h` header file. This discrepancy causes th

01What is this vulnerability?

Wasmtime is a standalone runtime for WebAssembly. Prior to version 2.0.2, there is a bug in Wasmtime's C API implementation where the definition of the `wasmtime_trap_code` does not match its declared signature in the `wasmtime/trap.h` header file. This discrepancy causes the function implementation to perform a 4-byte write into a 1-byte buffer provided by the caller. This can lead to three zero…

02Affected products

Vendor	Product	Versions
bytecodealliance	wasmtime	< 2.0.2

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2022-11-10T00:00:00.000Z
• Last modified: 2025-04-23T16:39:05.163Z

09References

• github.com — https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-h84q-m8rr-…
• github.com — https://github.com/bytecodealliance/wasmtime/commit/087d9d7becf7422b3f872a3bcd5d…