CVE-2022-39394
wasmtime_trap_code C API function has out of bounds write 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 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.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- High
- Privileges needed
- High
- User interaction
- Required
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
wasmtime_trap_code C API function has out of bounds write 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 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.
- Record
CVE-2022-39394- CVSS 3.1
- 3.8 Low
CVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:L - Weakness
- CWE-787
- Updated
- 2026-11-02
EUVDEUVD-2024-0651
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.
- Record
EUVD-2024-0651- CVSS 3.1
- 3.8 Low
CVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:L - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-h84q-m8rr-3v9q
wasmtime_trap_code C API function has out of bounds write vulnerability
Impact
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.
Patches
This bug has been patched and users should upgrade to Wasmtime 2.0.2.
Workarounds
This 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.
References
For more information
If you have any questions or comments about this advisory:
- Reach out to us on the Bytecode Alliance Zulip chat
- Open an issue in the bytecodealliance/wasmtime repository
- Record
GHSA-h84q-m8rr-3v9q- CVSS 3.1
- 3.8 Low
CVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:L - Weakness
- CWE-787
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2022-39394- CVSS 3.1
- 3.8 Low
CVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:L - CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-787
- Updated
- 2026-11-02
OSV
wasmtime_trap_code C API function has out of bounds write 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 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.
- Record
CVE-2022-39394- CVSS 3.1
- 3.8 Low
CVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:L - Weakness
- CWE-787
- Updated
- 2026-11-02
OSVGHSA-h84q-m8rr-3v9q
wasmtime_trap_code C API function has out of bounds write vulnerability
Impact
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.
Patches
This bug has been patched and users should upgrade to Wasmtime 2.0.2.
Workarounds
This 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.
References
For more information
If you have any questions or comments about this advisory:
- Reach out to us on the Bytecode Alliance Zulip chat
- Open an issue in the bytecodealliance/wasmtime repository
- Record
GHSA-h84q-m8rr-3v9q- CVSS 3.1
- 3.8 Low
CVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:L - Weakness
- CWE-787
- Updated
- 2026-11-02
OSVRUSTSEC-2022-0097
Out of bounds write in `wasmtime_trap_code` C API function
This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-h84q-m8rr-3v9q. For more information see the GitHub-hosted security advisory.
- Record
RUSTSEC-2022-0097- CVSS 3.1
- 3.8 Low
CVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:L - Updated
- 2026-11-02
OSVUBUNTU-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.
- Record
UBUNTU-CVE-2022-39394- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 3.1
- 3.8 Low
CVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:L - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
wasmtimecrates.io |
2.0.0 up to 2.0.2 | 2.0.2 |
wasmtimecrates.io |
before 1.0.2 | 1.0.2 |
wasmtimecrates.io |
0.0.0-0 up to 1.0.2, 2.0.0 up to 2.0.2 | 1.0.22.0.2 |
mozjs52Ubuntu:18.04:LTS |
All versions, plus listed versions 52.3.1-0ubuntu352.3.1-7fakesync152.8.1-0ubuntu0.18.04.152.9.1-0ubuntu0.18.04.1 |
None known |
mozjs38Ubuntu:18.04:LTS |
All versions, plus listed versions 38.8.0~repack1-0ubuntu138.8.0~repack1-0ubuntu338.8.0~repack1-0ubuntu4 |
None known |
mozjs68Ubuntu:20.04:LTS |
All versions, plus listed versions 68.5.0-1~fakesync68.5.0-2~fakesync68.6.0-168.6.0-1ubuntu1 |
None known |
mozjs52Ubuntu:20.04:LTS |
All versions, plus listed versions 52.9.1-1build152.9.1-1ubuntu3 |
None known |
mozjs78Ubuntu:22.04:LTS |
All versions, plus listed versions 78.13.0-178.15.0-278.15.0-4ubuntu1 |
None known |
mozjs91Ubuntu:22.04:LTS |
All versions, plus listed versions 91.5.1-0ubuntu191.6.0-191.6.0-291.7.0-291.10.0-0ubuntu1 |
None known |
thunderbirdUbuntu:22.04:LTS |
All versions, plus listed versions 1:91.1.2+build1-0ubuntu11:91.3.0+build2-0ubuntu11:91.3.1+build1-0ubuntu11:91.3.2+build1-0ubuntu11:91.4.0+build1.1-0ubuntu1 Show 34 moreShow less1:91.4.0+build2-0ubuntu11:91.5.0+build1-0ubuntu11:91.5.1+build1-0ubuntu11:91.6.1+build1-0ubuntu11:91.7.0+build1-0ubuntu11:91.7.0+build2-0ubuntu11:91.8.0+build2-0ubuntu11:91.9.1+build1-0ubuntu0.22.04.11:91.11.0+build2-0ubuntu0.22.04.11:102.2.2+build1-0ubuntu0.22.04.11:102.4.2+build2-0ubuntu0.22.04.11:102.7.1+build2-0ubuntu0.22.04.11:102.8.0+build2-0ubuntu0.22.04.11:102.9.0+build1-0ubuntu0.22.04.11:102.10.0+build2-0ubuntu0.22.04.11:102.11.0+build1-0ubuntu0.22.04.11:102.13.0+build1-0ubuntu0.22.04.11:102.15.0+build1-0ubuntu0.22.04.11:102.15.1+build1-0ubuntu0.22.04.11:115.3.1+build1-0ubuntu0.22.04.21:115.4.1+build1-0ubuntu0.22.04.11:115.5.0+build1-0ubuntu0.22.04.11:115.6.0+build2-0ubuntu0.22.04.11:115.8.1+build1-0ubuntu0.22.04.11:115.9.0+build1-0ubuntu0.22.04.11:115.10.1+build1-0ubuntu0.22.04.11:115.11.0+build2-0ubuntu0.22.04.11:115.12.0+build3-0ubuntu0.22.04.11:115.13.0+build5-0ubuntu0.22.04.11:115.15.0+build1-0ubuntu0.22.04.11:115.16.0+build2-0ubuntu0.22.04.11:115.18.0+build1-0ubuntu0.22.04.11:128.12.0+build1-0ubuntu0.22.04.11:140.7.1+build1-0ubuntu0.22.04.1 |
None known |
thunderbirdUbuntu:24.04:LTS |
All versions, plus listed versions 1:115.3.1+build1-0ubuntu11:115.4.1+build1-0ubuntu11:115.4.3+build1-0ubuntu11:115.5.0+build1-0ubuntu11:115.5.1+build1-0ubuntu1 Show 9 moreShow less1:115.5.2+build2-0ubuntu11:115.6.0+build1-0ubuntu11:115.6.0+build2-0ubuntu11:115.6.1+build1-0ubuntu11:115.8.0+build1-0ubuntu11:115.8.1+build1+snap21:115.8.1+build1+snap32:1snap1-0ubuntu12:1snap1-0ubuntu3 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2022-39394 is a low vulnerability (CVSS 3.8) in Bytecodealliance Wasmtime, published November 7, 2022. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.42%, the 36th percentile. Fixed in wasmtime 2.0.2.
References
github.com/bytecodealliance/wasmtime/security/advisories/GHSA-h84q-m8rr-3v9q
nvd.nist.gov/vuln/detail/CVE-2022-39394
groups.google.com/a/bytecodealliance.org/g/sec-announce/c/c1HBDDJwNPA
rustsec.org/advisories/RUSTSEC-2022-0097.html