---
title: "CVE-2026-77178: Oracle VM VirtualBox - Out of Bounds Write"
description: "Oracle VM VirtualBox < 7.2.8 contains an out-of-bounds write caused by improper handling in pcnetReceiveNoSync in DevPCNet.cpp in the PCNet network device model, letting guest OS users cause memory corruption on the host OS, exploit requires guest OS access."
url: https://panop.io/threat-heartbeat/CVE-2026-77178/
---

# CVE-2026-77178 Oracle VM VirtualBox - Out of Bounds Write

Oracle VM VirtualBox < 7.2.8 contains an out-of-bounds write caused by improper handling in pcnetReceiveNoSync in DevPCNet.cpp in the PCNet network device model, letting guest OS users cause memory corruption on the host OS, exploit requires guest OS access.

CVSS base score 9.1 /10

Critical

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.34% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-77178)

## Details

Type

Out of Bounds Write

Impact

Out Of Bounds Rw

CVSS vector

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

Published

6 October 2026

Updated

15 October 2026

Weakness

[CWE-787](https://cwe.mitre.org/data/definitions/787.html)

## Vendor fix

Update to version 7.2.8 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-2026-77178](https://nvd.nist.gov/vuln/detail/CVE-2026-77178)
- [https://www.oracle.com/](https://www.oracle.com/)
- [https://www.virtualbox.org/wiki/Download\_Old\_Builds\_7\_0](https://www.virtualbox.org/wiki/Download_Old_Builds_7_0)
- [https://gist.github.com/entropy1337/cd0d5b368445d20c43aca2590b313892](https://gist.github.com/entropy1337/cd0d5b368445d20c43aca2590b313892)

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## 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

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