CVE-2025-64345
Wasmtime provides unsound API access to a WebAssembly shared linear memory
Description
Wasmtime is a runtime for WebAssembly. Prior to version 38.0.4, 37.0.3, 36.0.3, and 24.0.5, Wasmtime's Rust embedder API contains an unsound interaction where a WebAssembly shared linear memory could be viewed as a type which provides safe access to the host (Rust) to the contents of the linear memory. This is not sound for shared linear memories, which could be modified in parallel, and this could lead to a data race in the host. Patch releases have been issued for all supported versions of Wasmtime, notably: 24.0.5, 36.0.3, 37.0.3, and 38.0.4. These releases reject creation of shared memories via `Memory::new` and shared memories are now excluded from core dumps. As a workaround, eembeddings affected by this issue should use `SharedMemory::new` instead of `Memory::new` to create shared memories. Affected embeddings should also disable core dumps if they are unable to upgrade. Note that core dumps are disabled by default but the wasm threads proposal (and shared memory) is enabled by default.
INFO
Published Date :
Nov. 12, 2025, 10:15 p.m.
Last Modified :
Oct. 18, 2026, 8:10 p.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | LOW | [email protected] | ||||
| CVSS 3.1 | LOW | MITRE-CVE |
Solution
- Upgrade Wasmtime to a patched version.
- Use SharedMemory::new for shared memories.
- Disable core dumps if unable to upgrade.
Public PoC/Exploit Available at Github
CVE-2025-64345 has a 2 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-64345.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-64345 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-64345
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
None
Protection against sophisticated Layer 4 (TCP/UDP) and Layer 7 (HTTP/S) DDoS attacks
ddos-protection waf
Rust Shell Makefile Dockerfile JavaScript HTML CSS TypeScript Astro MDX
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-64345 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-64345 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Translated by [email protected]
Oct. 18, 2026
Action Type Old Value New Value Added Translation Title: Wasmtime de bytecodealliance, Description: Wasmtime es un entorno de ejecución para WebAssembly. Versiones anteriores a la 38.0.4, 37.0.3, 36.0.3 y 24.0.5, la API del incrustador Rust de Wasmtime contiene una interacción insegura donde una memoria lineal compartida de WebAssembly podría ser vista como un tipo que proporciona acceso seguro al host (Rust) a los contenidos de la memoria lineal. Esto no es seguro para memorias lineales compartidas, las cuales podrían ser modificadas en paralelo, y esto podría llevar a una condición de carrera de datos en el host. Se han emitido lanzamientos de parches para todas las versiones compatibles de Wasmtime, en particular: 24.0.5, 36.0.3, 37.0.3 y 38.0.4. Estas versiones rechazan la creación de memorias compartidas a través de 'Memory::new' y las memorias compartidas ahora están excluidas de los volcados de memoria. Como solución alternativa, las incrustaciones afectadas por este problema deberían usar 'SharedMemory::new' en lugar de 'Memory::new' para crear memorias compartidas. Las incrustaciones afectadas también deberían deshabilitar los volcados de memoria si no pueden actualizar. Tenga en cuenta que los volcados de memoria están deshabilitados por defecto, pero la propuesta de hilos wasm (y la memoria compartida) está habilitada por defecto. -
CVE Modified by [email protected]
Jun. 17, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'bytecodealliance', 'product': 'wasmtime', 'versions': [{'status': 'affected', 'version': '>= 38.0.1, < 38.0.4'}, {'status': 'affected', 'version': '>= 37.0.0, < 37.0.3'}, {'status': 'affected', 'version': '>= 26.0.0, < 36.0.3'}, {'status': 'affected', 'version': '< 24.0.5'}]}] -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 17, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2025-64345', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2025-11-12T21:40:25.293462Z'} -
New CVE Received by [email protected]
Nov. 12, 2025
Action Type Old Value New Value Added Description Wasmtime is a runtime for WebAssembly. Prior to version 38.0.4, 37.0.3, 36.0.3, and 24.0.5, Wasmtime's Rust embedder API contains an unsound interaction where a WebAssembly shared linear memory could be viewed as a type which provides safe access to the host (Rust) to the contents of the linear memory. This is not sound for shared linear memories, which could be modified in parallel, and this could lead to a data race in the host. Patch releases have been issued for all supported versions of Wasmtime, notably: 24.0.5, 36.0.3, 37.0.3, and 38.0.4. These releases reject creation of shared memories via `Memory::new` and shared memories are now excluded from core dumps. As a workaround, eembeddings affected by this issue should use `SharedMemory::new` instead of `Memory::new` to create shared memories. Affected embeddings should also disable core dumps if they are unable to upgrade. Note that core dumps are disabled by default but the wasm threads proposal (and shared memory) is enabled by default. Added CVSS V3.1 AV:L/AC:H/PR:H/UI:R/S:U/C:N/I:L/A:N Added CWE CWE-362 Added Reference https://docs.rs/wasmtime/latest/wasmtime/struct.Memory.html#method.new Added Reference https://docs.rs/wasmtime/latest/wasmtime/struct.SharedMemory.html#method.new Added Reference https://docs.wasmtime.dev/stability-release.html Added Reference https://github.com/bytecodealliance/wasmtime/commit/9ebb6934f00d58b92fb68ed0e0b16c0ae828ca10 Added Reference https://github.com/bytecodealliance/wasmtime/releases/tag/v38.0.4 Added Reference https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-hc7m-r6v8-hg9q