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-2026-34942 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 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-2026-34942

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-2026-34942 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-2026-34941 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 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 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...

CVE-2026-34941

Wasmtime (WebAssembly runtime) contains a heap OOB read during transcoding of UTF-16 to the latin1+utf16 component-model encoding. The bug stems from validating the input length by code units instead of by byte length, causing reads beyond the WebAssembly linear memory during bounds checking. In ...

auto-wasi (=0.1.0), candid-extractor (>=0.1.0 <=0.1.2) +105 more potentially affected by CVE-2026-34943 via wasmtime (>=0.10.0 <=1.0.2)

wasmtime CARGO version =0.10.0, =0.1.0, =0.1.0, =0.1.0, =0.1.1, =0.5.3-0, =0.4.0, =0.4.0, =0.0.0, =0.5.0, =0.0.1-alpha, =0.40.1, =0.45.0, =0.1.0, =0.3.0 and more Source cves: CVE-2026-34943 Source advisory: OSV:RUSTSEC-2026-0085...

Miscompiled guest heap access enables sandbox escape on aarch64 Cranelift

This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-jhxm-h53p-jm7w For more information see the GitHub-hosted security advisory...

Wasmtime segfault or unused out-of-sandbox load with `f64x2.splat` operator on Cranelift x86-64

This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-qqfj-4vcm-26hv 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...

Improperly masked return value from `table.grow` with Winch compiler backend

This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-f984-pcp8-v2p7 For more information see the GitHub-hosted security advisory...

Wasmtime with Winch compiler backend may allow a sandbox-escaping memory access

This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-xx5w-cvp6-jv83 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...

Host panic when Winch compiler executes `table.fill`

This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-q49f-xg75-m9xw For more information see the GitHub-hosted security advisory...