ZDI-26-537: (Pwn2Own) Microsoft Windows storport Integer Overflow 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
- 7.8
- EPSS
- 0%
Affected versions
Key insight
The vulnerability was demonstrated at Pwn2Own, indicating an available exploit; a local attacker with low privileges can gain system privileges.
Description
The vulnerability CVE-2026-65814 affects the storport driver in Microsoft Windows. An integer overflow allows a local attacker who can already execute low-privileged code to escalate to system privileges. ZDI has assigned a CVSS rating of 8.8. The vulnerability was demonstrated at the Pwn2Own competition. Microsoft Windows installations are affected; the advisory does not provide patch information.
Risk score
- cvss base
- 78.00
- kev bonus
- 0.00
- epss bonus
- 0.00
- poc bonus
- 15.00
- raw before weight
- 93.00
- industry weight
- 1.21
- freshness factor
- 0.50
- exploitability factor
- 1.00
- days old
- 31.00
- vendor mismatch penalty
- 0.00
Path: operational
MITRE ATT&CK mapping
1 TTPProcedure details
| Technique | Tactic | Procedure | Conf. | Source |
|---|---|---|---|---|
| T1068 Exploitation for Privilege Escalation | Privilege Escalation | After obtaining low-privileged code execution on the target Windows system, the attacker exploits an integer overflow vulnerability in the storport driver to escalate privileges to SYSTEM or higher integrity level. | high | llm |