---
id: CVE-2026-115380
title: >-
  Wasmtime before 36.0.17, 37.0.0 before 48.0.4, and 49.0.0 before 49.0.2 Fuel
  Limit Bypass DoS via WASI Preview 0 poll_oneoff
summary: >-
  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
  poll_oneoff adapter, which performs O(n) host work per subscription without
  consuming …
severity: medium
cvss: 4
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'
cvssSource: cna
cwe:
  - CWE-770
vendor: bytecodealliance
product: wasmtime
affected:
  - wasmtime < 36.0.17
  - wasmtime >= 37.0.0 < 48.0.4
  - wasmtime >= 49.0.0 < 49.0.2
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-10-26T19:27:18.578210Z'
published: '2026-10-22'
updated: '2026-10-26'
sourceUpdated: '2026-10-26T19:38:30.038Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-115380'
references:
  - url: >-
      https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-j366-h8gg-77pm
    label: GitHub Security Advisory (GHSA-j366-h8gg-77pm)
  - url: >-
      https://www.vulncheck.com/advisories/wasmtime-before-36.0.17-37.0.0-before-48.0.4-and-49.0.0-before-49.0.2-fuel-limit-bypass-dos-via-wasi-preview-0-poll-oneoff
    label: >-
      VulnCheck Advisory: Wasmtime before 36.0.17, 37.0.0 before 48.0.4, and
      49.0.0 before 49.0.2 Fuel Limit Bypass DoS via WASI Preview 0 poll_oneoff
  - url: 'https://crates.io/crates/wasmtime-wasi'
  - url: 'https://rustsec.org/advisories/RUSTSEC-2026-0321.html'
  - url: 'https://github.com/bytecodealliance/wasmtime/pull/14481'
tags:
  - cve.org
  - osv
  - rust
epss: 0.00118
epssPercentile: 0.01722
aliases:
  - RUSTSEC-2026-0321
  - GHSA-j366-h8gg-77pm
ecosystem: rust
patched:
  - wasmtime-wasi 49.0.2
ingestedAt: '2026-10-22T22:00:50.403Z'
---

## Overview

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 poll_oneoff adapter, which performs O(n) host work per subscription without consuming or checking fuel. Malicious guest modules can pass many subscriptions to force long-running host computation that ignores configured fuel limits.

## Affected

- `wasmtime < 36.0.17`
- `wasmtime >= 37.0.0 < 48.0.4`
- `wasmtime >= 49.0.0 < 49.0.2`

## Remediation

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

## Package advisory (CVE-2026-115380)

Affected packages:

- `wasmtime-wasi >= 49.0.0, < 49.0.2`

Patched in:

- `wasmtime-wasi 49.0.2`

Source: https://osv.dev/vulnerability/RUSTSEC-2026-0321