How severe is CVE-2022-39394?

CVE-2022-39394 has a CVSS 3.x base score of 3.8, rated low severity. It is exploitable over local access with high attack complexity, requires high privileges and user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2022-39394 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (23rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2022-39394?

CVE-2022-39394 affects Bytecodealliance Wasmtime. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2022-39394?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2022-39394 published?

CVE-2022-39394 was published on 2022-11-10 and last updated on 2026-06-17.

CVE-2022-39394

CVE-2022-39394 is a low-severity vulnerability in Bytecodealliance Wasmtime with a CVSS 3.x base score of 3.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.

Key facts

Severity: Low (CVSS 3.x base score 3.8)
EPSS exploit prediction: 0% (23rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Bytecodealliance Wasmtime
Published: 2022-11-10
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2022-39394?: 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.
How severe is CVE-2022-39394?: CVE-2022-39394 has a CVSS 3.x base score of 3.8, rated low severity. It is exploitable over local access with high attack complexity, requires high privileges and user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2022-39394 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (23rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2022-39394?: CVE-2022-39394 affects Bytecodealliance Wasmtime. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2022-39394?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2022-39394 published?: CVE-2022-39394 was published on 2022-11-10 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:rust:*:*

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