Vulnerability · Published Oct 6, 2026 · Assigned by mitre
CVE-2026-77178
Critical 9.1
In plain English
A critical-severity out-of-bounds write in the virtualbox package (Ubuntu). There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 27% of all known vulnerabilities).
Severity (CVSS 3.1)9.1Critical
Exploit odds (30 days)0.3%top 73.0% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Oracle VM VirtualBox before 7.2.8 allows guest OS users to cause an out-of-bounds write in the host OS in pcnetReceiveNoSync in DevPCNet.cpp in the PCNet (Am79C970A) network device model.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu:22.04:LTS | virtualbox | no fix listed | UBUNTU-CVE-2026-77178 |
| Ubuntu:24.04:LTS | virtualbox | no fix listed | UBUNTU-CVE-2026-77178 |
| Ubuntu:26.04:LTS | virtualbox | no fix listed | UBUNTU-CVE-2026-77178 |
| Ubuntu:26.10 | virtualbox | no fix listed | UBUNTU-CVE-2026-77178 |
Affected products (as reported)
Weakness: CWE-787 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H