CVE-2026-35195 Wasmtime has an out-of-bounds write or crash when transcoding component model strings

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...

CVE-2026-35195 Wasmtime has an out-of-bounds write or crash when transcoding component model strings

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...

CVE-2026-34943

Wasmtime (WebAssembly runtime) has a vulnerability where lifting a flags-typed component-model value with Val can panic if bits outside the allowed flags set are present. Affected versions before fixes include 24.0.7, 36.0.7, 42.0.2, and 43.0.1; the panic occurs in Wasmtime’s Val lifting (not in ...

CVE-2026-34943 Wasmtime panics when lifting `flags` component value

Wasmtime is a runtime for WebAssembly. Prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1, Wasmtime contains a possible panic which can happen when a flags-typed component model value is lifted with the Val type. If bits are set outside of the set of flags the component model specifies that these bits...

CVE-2026-34943

Wasmtime is a runtime for WebAssembly. Prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1, Wasmtime contains a possible panic which can happen when a flags-typed component model value is lifted with the Val type. If bits are set outside of the set of flags the component model specifies that these bits...

CVE-2026-34943

Wasmtime is a runtime for WebAssembly. Prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1, Wasmtime contains a possible panic which can happen when a flags-typed component model value is lifted with the Val type. If bits are set outside of the set of flags the component model specifies that these bits...

CVE-2026-34942 Wasmtime panics when transcoding misaligned utf-16 strings

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 into the Component Model's utf16 or latin1+utf16 encodings improperly verified the alignment of reallocated strings. This meant that unaligned pointers could be...

CVE-2026-34942

Wasmtime VM exposes a DoS risk due to a panic-triggering path when transcoding strings into utf16/latin1+utf16. Root cause: alignment verification for reallocated strings was improper, allowing unaligned pointers to be passed to the host by a malicious guest. Affected versions prior to fixed rele...

CVE-2026-34941 Wasmtime has a Heap OOB read in component model UTF-16 to latin1+utf16 string transcoding

Wasmtime is a runtime for WebAssembly. Prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1, Wasmtime contains a vulnerability where when transcoding a UTF-16 string to the latin1+utf16 component-model encoding it would incorrectly validate the byte length of the input string when performing a bounds chec...

CVE-2026-34941 Wasmtime has a Heap OOB read in component model UTF-16 to latin1+utf16 string transcoding

Wasmtime is a runtime for WebAssembly. Prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1, Wasmtime contains a vulnerability where when transcoding a UTF-16 string to the latin1+utf16 component-model encoding it would incorrectly validate the byte length of the input string when performing a bounds chec...

CVE-2026-34941 Wasmtime has a Heap OOB read in component model UTF-16 to latin1+utf16 string transcoding

Wasmtime is a runtime for WebAssembly. Prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1, Wasmtime contains a vulnerability where when transcoding a UTF-16 string to the latin1+utf16 component-model encoding it would incorrectly validate the byte length of the input string when performing a bounds chec...

RUSTSEC-2026-0093 Heap OOB read in component model UTF-16 to latin1+utf16 string transcoding

This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-hx6p-xpx3-jvvv For more information see the GitHub-hosted security advisory...

RUSTSEC-2026-0091 Out-of-bounds write or crash when transcoding component model strings

This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-394w-hwhg-8vgm For more information see the GitHub-hosted security advisory...

Heap OOB read in component model UTF-16 to latin1+utf16 string transcoding

This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-hx6p-xpx3-jvvv For more information see the GitHub-hosted security advisory...

Out-of-bounds write or crash when transcoding component model strings

This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-394w-hwhg-8vgm For more information see the GitHub-hosted security advisory...

PT-2026-31681

Name of the Vulnerable Software and Affected Versions Wasmtime versions prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1 Description Wasmtime's implementation of transcoding strings into the Component Model's utf16 or latin1+utf16 encodings did not properly verify the alignment of reallocated strings...

CVE-2026-34941: Out-of-bounds Read

Wasmtime is a runtime for WebAssembly. Prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1, Wasmtime contains a vulnerability where when transcoding a UTF-16 string to the latin1+utf16 component-model encoding it would incorrectly validate the byte length of the input string when performing a bounds chec...

CVE-2026-34943: Uncaught Exception

Wasmtime is a runtime for WebAssembly. Prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1, Wasmtime contains a possible panic which can happen when a flags-typed component model value is lifted with the Val type. If bits are set outside of the set of flags the component model specifies that these bits...

Linux Distros Unpatched Vulnerability : CVE-2026-34943

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - Wasmtime is a runtime for WebAssembly. Prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1, Wasmtime contains a possible panic which can happen when a flags-typed...

Linux Distros Unpatched Vulnerability : CVE-2026-34942

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - 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 into the Component Model's...