---
id: CVE-2026-115893
title: >-
  Wasmtime: Cranelift backend on aarch64 can jump to incorrect target on large
  Wasm `br_table` instruction
summary: >-
  Wasmtime is a runtime for WebAssembly. Prior to 36.0.19, 48.0.7, and 49.0.4,
  the Cranelift compiler backend on aarch64 can compile a Wasm br_table
  instruction with more than approximately 256,000 targets so that it has an
  incorrect condi…
severity: critical
cvss: 9.9
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H'
cvssSource: cna
cwe:
  - CWE-691
vendor: bytecodealliance
product: wasmtime
affected:
  - wasmtime < 36.0.19
  - 'wasmtime >= 37.0.0, < 48.0.7'
  - 'wasmtime >= 49.0.0, < 49.0.4'
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-29T18:19:46.559873Z'
exploitAvailable: true
published: '2026-10-23'
updated: '2026-10-29'
sourceUpdated: '2026-10-29T18:20:01.899Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-115893'
references:
  - url: >-
      https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-mghf-wjfp-p5xm
    label: >-
      https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-mghf-wjfp-p5xm
  - url: 'https://github.com/bytecodealliance/wasmtime/pull/14818'
    label: 'https://github.com/bytecodealliance/wasmtime/pull/14818'
  - url: 'https://github.com/bytecodealliance/wasmtime/pull/14819'
    label: 'https://github.com/bytecodealliance/wasmtime/pull/14819'
  - url: 'https://github.com/bytecodealliance/wasmtime/pull/14820'
    label: 'https://github.com/bytecodealliance/wasmtime/pull/14820'
  - url: 'https://github.com/bytecodealliance/wasmtime/pull/14826'
    label: 'https://github.com/bytecodealliance/wasmtime/pull/14826'
  - url: >-
      https://github.com/bytecodealliance/wasmtime/commit/222ff3a65dab9aa7011f8c246937751a0bac5abd
    label: >-
      https://github.com/bytecodealliance/wasmtime/commit/222ff3a65dab9aa7011f8c246937751a0bac5abd
  - url: >-
      https://github.com/bytecodealliance/wasmtime/commit/994549891c8a706cb4f2809f9d17b9f67b31e618
    label: >-
      https://github.com/bytecodealliance/wasmtime/commit/994549891c8a706cb4f2809f9d17b9f67b31e618
  - url: >-
      https://github.com/bytecodealliance/wasmtime/commit/e61df1b454be9313d61a5f8de07722a421139bbe
    label: >-
      https://github.com/bytecodealliance/wasmtime/commit/e61df1b454be9313d61a5f8de07722a421139bbe
  - url: >-
      https://github.com/bytecodealliance/wasmtime/commit/f517bd6e890c7c1291ab9fe05d8cc0c9f11e56aa
    label: >-
      https://github.com/bytecodealliance/wasmtime/commit/f517bd6e890c7c1291ab9fe05d8cc0c9f11e56aa
  - url: 'https://github.com/bytecodealliance/wasmtime/releases/tag/v36.0.19'
    label: 'https://github.com/bytecodealliance/wasmtime/releases/tag/v36.0.19'
  - url: 'https://github.com/bytecodealliance/wasmtime/releases/tag/v48.0.7'
    label: 'https://github.com/bytecodealliance/wasmtime/releases/tag/v48.0.7'
  - url: 'https://github.com/bytecodealliance/wasmtime/releases/tag/v49.0.4'
    label: 'https://github.com/bytecodealliance/wasmtime/releases/tag/v49.0.4'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-115893'
  - url: 'https://rustsec.org/advisories/RUSTSEC-2026-0379.html'
  - url: 'https://github.com/advisories/GHSA-mghf-wjfp-p5xm'
  - url: 'https://github.com/bytecodealliance/wasmtime'
  - url: 'https://crates.io/crates/wasmtime'
tags:
  - cve.org
  - ghsa
  - rust
  - exploit-available
  - osv
aliases:
  - GHSA-mghf-wjfp-p5xm
  - RUSTSEC-2026-0379
ecosystem: rust
patched:
  - wasmtime 36.0.19
  - wasmtime 48.0.7
  - wasmtime 49.0.4
epss: 0.0099
epssPercentile: 0.62523
exploits:
  github: 1
  githubRepos:
    - >-
      https://github.com/shreyas-malhotra/CVE-2026-115893-wasmtime-sandbox-escape
  checkedAt: '2026-11-01T17:58:21.188Z'
ingestedAt: '2026-10-23T21:38:13.047Z'
---

## Overview

Wasmtime is a runtime for WebAssembly. Prior to 36.0.19, 48.0.7, and 49.0.4, the Cranelift compiler backend on aarch64 can compile a Wasm br_table instruction with more than approximately 256,000 targets so that it has an incorrect conditional branch target. The branch can then jump to arbitrary other code at a user-controlled offset, allowing a user-controlled Wasm module to escape the sandbox on aarch64 engines using the default Cranelift backend. This issue is fixed in versions 36.0.19, 48.0.7, and 49.0.4.

## Affected

- `wasmtime < 36.0.19`
- `wasmtime >= 37.0.0, < 48.0.7`
- `wasmtime >= 49.0.0, < 49.0.4`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-115893)

Affected packages:

- `wasmtime < 36.0.19`
- `wasmtime >= 37.0.0, < 48.0.7`
- `wasmtime >= 49.0.0, < 49.0.4`

Patched in:

- `wasmtime 36.0.19`
- `wasmtime 48.0.7`
- `wasmtime 49.0.4`

Source: https://github.com/advisories/GHSA-mghf-wjfp-p5xm