CVE-2022-39394

Name: CVE-2022-39394
Creator: NVD / NIST
Published: 2022-11-10T20:15:11.85+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 0.32%

Last modified Jun 17, 2026

CVE-2022-39394 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. 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. EPSS estimates a 0.32% chance of exploitation in the next 30 days.

Description

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 bytes being written beyond the 1-byte location provided by the caller. This bug has been patched and users should upgrade to Wasmtime 2.0.2. This bug can be worked around by providing a 4-byte buffer casted to a 1-byte buffer when calling `wasmtime_trap_code`. Users of the `wasmtime` crate are not affected by this issue, only users of the C API function `wasmtime_trap_code` are affected.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.32%

23.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Bytecodealliance	Wasmtime	< 1.0.2
Bytecodealliance	Wasmtime	>= 2.0.0, < 2.0.2

References

https://github.com/bytecodealliance/wasmtime/commit/087d9d7becf7422b3f872a3bcd5d97bb7ce7ff36Patch, Third Party Advisory
https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-h84q-m8rr-3v9qThird Party Advisory
https://github.com/bytecodealliance/wasmtime/commit/087d9d7becf7422b3f872a3bcd5d97bb7ce7ff36Patch, Third Party Advisory
https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-h84q-m8rr-3v9qThird Party Advisory

Timeline

Published: Nov 10, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2022-39394?

How severe is CVE-2022-39394?

CVE-2022-39394 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 0.32% probability of exploitation in the next 30 days.

How do I fix CVE-2022-39394?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2022-39394?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST