CVE-2026-115892

Wasmtime is a runtime for WebAssembly. From 46.0.0 until 48.0.7 and 49.0.4, lowering a host-created component-model stream or future into a guest can omit a required payload-type check after the value passes through guest code and returns through StreamAny, FutureAny, Val::Stream, Val::Future, or...

GHSA-9PVW-HWFG-92H5 Wasmtime: Panic lowering a host-created component model stream into a guest that expects a different payload type

Summary Wasmtime may panic when the host lowers a component model stream or future into a guest, if the host created that stream or future with one payload type and the guest expects a different one. This can happen when an embedder creates a stream or future, passes it through a guest, receives ...

CVE-2026-115892

The Wasmtime runtime is vulnerable to a Denial of Service (DoS) due to a flaw in how it handles asynchronous streams or futures exchanged between the host and the guest. Specifically, versions 46.0.0 through 48.0.7 and 49.0.4 fail to perform required payload-type checks when values return through...

EUVD-2026-109187

Wasmtime is a runtime for WebAssembly. From 46.0.0 until 48.0.7 and 49.0.4, lowering a host-created component-model stream or future into a guest can omit a required payload-type check after the value passes through guest code and returns through StreamAny, FutureAny, Val::Stream, Val::Future, or...

CVE-2026-115892 Wasmtime: Panic lowering a host-created component model stream into a guest that expects a different payload type

Wasmtime is a runtime for WebAssembly. From 46.0.0 until 48.0.7 and 49.0.4, lowering a host-created component-model stream or future into a guest can omit a required payload-type check after the value passes through guest code and returns through StreamAny, FutureAny, Val::Stream, Val::Future, or...

RUSTSEC-2026-0378 Panic lowering a host-created component model stream into a guest that expects a different payload type

This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-9pvw-hwfg-92h5 For more information see the GitHub-hosted security advisory...

Panic lowering a host-created component model stream into a guest that expects a different payload type

This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-9pvw-hwfg-92h5 For more information see the GitHub-hosted security advisory...

RUSTSEC-2026-0355 Panic viewing component model stream or future as the wrong type

This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-63h4-6cx9-pjfj For more information see the GitHub-hosted security advisory...

RUSTSEC-2026-0363 Component-model handle tables are capped only per instance and charged to no limit

This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-q554-3cjc-rx7p For more information see the GitHub-hosted security advisory...

JLSEC-2026-1355 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 ...

JLSEC-2026-1364 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...

JLSEC-2026-1351 Wasmtime is vulnerable to panic when dropping a `[Typed]Func::call_async` future

The affected versions of Wasmtime can panic if the host embedder drops the future returned by wasmtime::component::TypedFunc::callasync before it resolves. Details Starting with Wasmtime 39.0.0, the component-model-async feature became the default, which brought with it a new implementation of...

JLSEC-2026-1354 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...

JLSEC-2026-1356 Wasmtime has a possible panic when lifting `flags` component value

Impact 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 should be ignored but Wasmtime will panic when this value is lifted. This pani...

CVE-2026-15380

A non-administrator interactive user can obtain full SYSTEM code execution through a DCOM/task scheduler logic chain — no network access, no memory corruption required ITMS 8.7.3...

SUSE 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...

EUVD-2026-21022

Wasmtime has a possible panic when lifting flags component value...

Wasmtime has a possible panic when lifting `flags` component value

Impact 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 should be ignored but Wasmtime will panic when this value is lifted. This pani...

EUVD-2026-20990

Wasmtime: Panic when transcoding misaligned utf-16 strings...

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 ...