CVE-2026-35195 (GCVE-0-2026-35195)
Vulnerability from cvelistv5
Published
2026-04-09 18:55
Modified
2026-04-13 15:38
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-787 - Out-of-bounds Write
Summary
Wasmtime is a runtime for WebAssembly. Prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1, Wasmtime's implementation of transcoding strings between components contains a bug where the return value of a guest component's realloc is not validated before the host attempts to write through the pointer. This enables a guest to cause the host to write arbitrary transcoded string bytes to an arbitrary location up to 4GiB away from the base of linear memory. These writes on the host could hit unmapped memory or could corrupt host data structures depending on Wasmtime's configuration. Wasmtime by default reserves 4GiB of virtual memory for a guest's linear memory meaning that this bug will by default on hosts cause the host to hit unmapped memory and abort the process due to an unhandled fault. Wasmtime can be configured, however, to reserve less memory for a guest and to remove all guard pages, so some configurations of Wasmtime may lead to corruption of data outside of a guest's linear memory, such as host data structures or other guests's linear memories. This vulnerability is fixed in 24.0.7, 36.0.7, 42.0.2, and 43.0.1.
References
| URL | Tags | |
|---|---|---|
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| bytecodealliance | wasmtime |
Version: < 24.0.7 Version: >= 25.0.0, < 36.0.7 Version: >= 37.0.0, < 42.0.2 Version: >= 43.0.0, < 44.0.1 |
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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