CVE-2026-70307: Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability
Use after free in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
CSIRTS triage
- What
- Use-after-free vulnerability in Windows Ancillary Function Driver for WinSock allows privilege escalation.
- Who is affected
- Authenticated local users on Windows systems.
- Urgency
- High severity (CVSS 7.0) requiring valid account access; patch promptly.
- Action
- Apply latest Windows security patches.
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-70307
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Low exploitation riskCVE-2026-703070.32% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 24% of all EPSS-scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-70307 | coverage & exploitation status | NVD · CVE.org |
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