https://cve.radiocsirt.org/rss/recent/all/10 Most recent entries from all 2026-10-03T19:26:31.769212+00:00 Vulnerability-Lookup csirt@opendfir.org python-feedgen Contains only the most 10 recent entries. https://cve.radiocsirt.org/vuln/cve-2026-34943 CVE-2026-34943 — Wasmtime panics when lifting `flags` component value 2026-10-03T19:26:31.821816+00:00

Affected: bytecodealliance wasmtime

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 should be ignored but Wasmtime will panic when this value is lifted. This panic only affects wasmtime's implementation of lifting into Val, not when using the flags! macro. This additionally only affects flags-typed values which are part of a WIT interface. This has the risk of being a guest-controlled panic within the host which Wasmtime considers a DoS vector. This vulnerability is fixed in 24.0.7, 36.0.7, 42.0.2, and 43.0.1.

 https://cve.radiocsirt.org/vuln/ghsa-m758-wjhj-p3jq GHSA-m758-wjhj-p3jq — Wasmtime has a possible panic when lifting `flags` component value 2026-10-03T19:26:31.821878+00:00

Affected: crates.io: wasmtime

### 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 panic only affects wasmtime's implementation of lifting into `Val`, not when using the `flags!` macro. This additionally only affects `flags`-typed values which are part of a WIT interface.

This has the risk of being a guest-controlled panic within the host which Wasmtime considers a DoS vector.

### Patches

Wasmtime 24.0.7, 36.0.7, 42.0.2, and 43.0.1 have been issued to fix this bug. Users are recommended to update to these patched versions of Wasmtime.

### Workarounds

There is no workaround for this bug if a host meets the criteria to be affected. To be affected a host must be using `wasmtime::component::Val` and possibly work with a `flags` type in the component model.