CVE-2026-34941

A flaw was found in Wasmtime, a runtime for WebAssembly. When transcoding a UTF-16 string to the latin1+utf16 component-model encoding, Wasmtime incorrectly validates the byte length of the input string, checking the number of code units instead of the actual byte length. This vulnerability can...

EUVD-2026-21039

Wasmtime has out-of-bounds write or crash when transcoding component model strings...

GHSA-394W-HWHG-8VGM Wasmtime has out-of-bounds write or crash when transcoding component model strings

Impact 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...

Wasmtime has out-of-bounds write or crash when transcoding component model strings

Impact 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...

GHSA-JXHV-7H78-9775 Wasmtime: Panic when transcoding misaligned utf-16 strings

Impact 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 passed to the host for transcoding which would trigger a host panic. This panic ...

EUVD-2026-20988

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

GHSA-HX6P-XPX3-JVVV Wasmtime: Heap OOB read in component model UTF-16 to latin1+utf16 string transcoding

Summary 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 check. Specifically the number of code units were checked instead of the byte...

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

Summary 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 check. Specifically the number of code units were checked instead of the byte...

CVE-2026-35195

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...

DEBIAN-CVE-2026-35195

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...

DEBIAN-CVE-2026-34941

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-2026-34942

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...

DEBIAN-CVE-2026-34942

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-2026-35195

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-2026-34941

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-2026-34942

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...

UBUNTU-CVE-2026-34941

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...

UBUNTU-CVE-2026-35195

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...

UBUNTU-CVE-2026-34942

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-2026-35195

The CVE-2026-35195 vulnerability affects Wasmtime (WebAssembly runtime) where the guest component’s realloc return value is not validated during transcoding of component-model strings. This can allow a guest to cause the host to write arbitrary transcoded string bytes to an arbitrary address up t...