---
title: "CVE-2026-115384: Wasmtime - Buffer Overflow"
description: "Wasmtime 39.0.0 < 48.0.4 and 49.0.0 < 49.0.2 contain a stack buffer overflow caused by unvalidated async callback result types in component-model-async callbacks, letting malicious guests overwrite return addresses to crash host or escape sandbox, exploit requires supplying mistyped async callbacks."
url: https://panop.io/threat-heartbeat/CVE-2026-115384/
---

# CVE-2026-115384 Wasmtime - Buffer Overflow

Wasmtime 39.0.0 < 48.0.4 and 49.0.0 < 49.0.2 contain a stack buffer overflow caused by unvalidated async callback result types in component-model-async callbacks, letting malicious guests overwrite return addresses to crash host or escape sandbox, exploit requires supplying mistyped async callbacks.

CVSS base score 9.9 /10

Critical

CISA KEV

Not listed

Public exploit

None known

Authentication

Required

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-115384)

## Details

Type

Buffer Overflow

Impact

Denial Of Service, Privilege Escalation

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Published

22 October 2026

Updated

23 October 2026

Weakness

[CWE-20](https://cwe.mitre.org/data/definitions/20.html)

## Vendor fix

Upgrade to versions 48.0.4 or later and 49.0.2 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-115384](https://nvd.nist.gov/vuln/detail/CVE-2026-115384)
- [https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-32h6-97mm-8q3c](https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-32h6-97mm-8q3c)
- [https://www.vulncheck.com/advisories/wasmtime-39.0.0-before-48.0.4-and-49.0.0-before-49.0.2-stack-buffer-overflow](https://www.vulncheck.com/advisories/wasmtime-39.0.0-before-48.0.4-and-49.0.0-before-49.0.2-stack-buffer-overflow)

[← All CVEs](https://panop.io/threat-heartbeat/)

## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

Panop answers these inside your environment, for this CVE and every other finding.

[Book a demo](https://panop.io/demo)