CVE-2026-115384

A flaw was found in Wasmtime. A malicious guest can trigger a stack-based buffer overflow by supplying asynchronous callback functions with mismatched result types. This vulnerability allows the guest to overwrite host stack memory, enabling them to escape the WebAssembly Wasm sandbox, potentiall...

CVE-2026-118688

wasmtime-wasi in Wasmtime before 36.0.18, 37.0.0 before 48.0.6, and 49.0.0 before 49.0.3 re-appends a trailing slash to rename source paths, causing renameat on macOS and FreeBSD hosts to follow directory symlinks. A guest with sandbox write access can rename a relative symlink such as "up/" to...

CVE-2026-118688 Wasmtime before 36.0.18, 37.0.0 before 48.0.6, and 49.0.0 before 49.0.3 Sandbox Escape via Symlink Rename

wasmtime-wasi in Wasmtime before 36.0.18, 37.0.0 before 48.0.6, and 49.0.0 before 49.0.3 re-appends a trailing slash to rename source paths, causing renameat on macOS and FreeBSD hosts to follow directory symlinks. A guest with sandbox write access can rename a relative symlink such as "up/" to...

EUVD-2026-112393

wasmtime-wasi in Wasmtime before 36.0.18, 37.0.0 before 48.0.6, and 49.0.0 before 49.0.3 re-appends a trailing slash to rename source paths, causing renameat on macOS and FreeBSD hosts to follow directory symlinks. A guest with sandbox write access can rename a relative symlink such as "up/" to...

CVE-2026-118688

The wasmtime-wasi component in Wasmtime versions before 36.0.18 , 37.0.0 before 48.0.6 , and 49.0.0 before 49.0.3 contains a vulnerability where it re-appends a trailing slash to rename source paths. This behavior causes the renameat system call on macOS and FreeBSD hosts to follow directory syml...

CVE-2026-118688 Wasmtime before 36.0.18, 37.0.0 before 48.0.6, and 49.0.0 before 49.0.3 Sandbox Escape via Symlink Rename

wasmtime-wasi in Wasmtime before 36.0.18, 37.0.0 before 48.0.6, and 49.0.0 before 49.0.3 re-appends a trailing slash to rename source paths, causing renameat on macOS and FreeBSD hosts to follow directory symlinks. A guest with sandbox write access can rename a relative symlink such as "up/" to...

PT-2026-129161

wasmtime-wasi in Wasmtime before 36.0.18, 37.0.0 before 48.0.6, and 49.0.0 before 49.0.3 re-appends a trailing slash to rename source paths, causing renameat on macOS and FreeBSD hosts to follow directory symlinks. A guest with sandbox write access can rename a relative symlink such as "up/" to...

Exploit for CVE-2026-115893

CVE-2026-115893: Wasmtime aarch64 Sandbox Escape A working fu...

Linux Distros Unpatched Vulnerability : CVE-2026-115385

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - Wasmtime 46.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains a denial of service vulnerability in the wasmtime-wasi WASIp3 implementation that allows guests ...

Linux Distros Unpatched Vulnerability : CVE-2026-115388

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - wasmtime-wasi-http in Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 does not enforce the wasi:io/streams check-write allowance for...

Linux Distros Unpatched Vulnerability : CVE-2026-115384

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - Wasmtime 39.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains a stack buffer overflow vulnerability that allows malicious guests to write 16KB to the native...

Wasmtime 49.0.3 AArch64 Sandbox Escape

Wasmtime versions before 36.0.19, 37.0.0 through 48.0.6, and 49.0.0 through 49.0.3 contain an AArch64 Cranelift brtable branch-target flaw. The proof of concept diverts execution to a JIT literal pool to demonstrate host code execution. https://packetstorm.news/download/237864...

Two Critical Wasmtime Flaws Could Let Malicious WebAssembly Modules Escape Sandboxes

Two critical flaws in Wasmtime, a WebAssembly runtime that can be built into other software, could allow a malicious WebAssembly module to escape the sandbox intended to contain it, the project's maintainers say. An attacker would first need a vulnerable Wasmtime build to compile a module they...

UBUNTU-CVE-2026-115384

Wasmtime 39.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains a stack buffer overflow vulnerability that allows malicious guests to write 16KB to the native stack via unvalidated async callback result types. Attackers can supply components with mistyped component-model-async callback functions ...

UBUNTU-CVE-2026-115380

Wasmtime before 36.0.17, 37.0.0 before 48.0.4, and 49.0.0 before 49.0.2 contains a denial of service vulnerability in the wasmtime-wasi WASI preview 0 polloneoff adapter, which performs On host work per subscription without consuming or checking fuel. Malicious guest modules can pass many...

UBUNTU-CVE-2026-115381

Wasmtime before 36.0.17, 37.0.0 before 48.0.4, and 49.0.0 before 49.0.2 contains an unbounded memory allocation in the wasmtime-wasi WASIp2 write-zeroes method of SinkOutputStream, the default stream used when stdout/stderr are not configured. A malicious WebAssembly guest can request huge...

UBUNTU-CVE-2026-115385

Wasmtime 46.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains a denial of service vulnerability in the wasmtime-wasi WASIp3 implementation that allows guests to abort the Unix host process. Guests with mutable preopened directory access can call set-times or set-times-at with negative seconds...

UBUNTU-CVE-2026-115386

Wasmtime before 36.0.17, 37.0.0 before 48.0.4, and 49.0.0 before 49.0.2 contains an information disclosure vulnerability in the WASIp1 fdreaddir implementation that copies uninitialized struct padding into guest memory. Guests with a preopened directory can list entries to receive three bytes of...

UBUNTU-CVE-2026-115388

wasmtime-wasi-http in Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 does not enforce the wasi:io/streams check-write allowance for WASIp2 outgoing HTTP bodies, so oversized writes succeed instead of trapping. A malicious guest can pass large buffers to write on...

UBUNTU-CVE-2026-115387

Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 contains a denial of service vulnerability in wasmtime-wasi that allows guest WASI programs to panic the host via overflowing filesystem timestamps. Attackers can pass atim or mtim values whose sub-second field overflows the...