ZDI-26-495: (Pwn2Own) VMware ESXi VMXNET3 espQueueMask Out-Of-Bounds Write Local Privilege Escalation Vulnerability
Admiralty grading (A–F · 1–6)
Source reliability
- A Completely reliable
- B Usually reliable
- C Fairly reliable
- D Not usually reliable
- E Unreliable
- F Cannot be judged
Information credibility
- 1 Confirmed
- 2 Probably true
- 3 Possibly true
- 4 Doubtful
- 5 Improbable
- 6 Cannot be judged
NATO Admiralty (AJP-2.1) grades confidence, independent of the risk score. Cross-source corroboration isn't tracked for non-CVE news, so single-source items are capped at a lower credibility number; a low number does not imply low quality.
Key metrics
- CVSS
- 9.3
- EPSS
- 0%
Key insight
An out-of-bounds write vulnerability in VMware ESXi VMXNET3 driver enables local attackers to escalate privileges on guest virtual machines; demonstrated at Pwn2Own 2026.
Description
CVE-2026-47876 is an out-of-bounds write vulnerability in the VMXNET3 network adapter driver on VMware ESXi that allows local attackers to escalate privileges on a guest virtual machine. Exploitation requires first obtaining the ability to execute high-privileged code on the target guest system. ZDI assigned a CVSS score of 8.2. The vulnerability was publicly demonstrated at Pwn2Own 2026.
Risk score
- cvss base
- 93.00
- kev bonus
- 0.00
- epss bonus
- 0.00
- poc bonus
- 15.00
- raw before weight
- 108.00
- industry weight
- 1.21
- freshness factor
- 0.50
- exploitability factor
- 1.00
- days old
- 41.00
- vendor mismatch penalty
- 0.00
Path: operational