Out-of-bounds Write Affecting wasmcloud package, versions <2.0.4-r0


Severity

Recommended
0.0
medium
0
10

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Threat Intelligence

EPSS
0.01% (2nd percentile)

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  • Snyk IDSNYK-CHAINGUARDLATEST-WASMCLOUD-16122132
  • published22 Apr 2026
  • disclosed9 Apr 2026

Introduced: 9 Apr 2026

NewCVE-2026-35195  (opens in a new tab)
CWE-787  (opens in a new tab)

How to fix?

Upgrade Chainguard wasmcloud to version 2.0.4-r0 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream wasmcloud package and not the wasmcloud package as distributed by Chainguard. See How to fix? for Chainguard relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1