CVE-2025-21418

Exploited in the Wild ✓ Confirmed 0-Day ★ Google Project Zero

Triaged: March 3, 2026 5 articles

VulnLookup ↗ NVD ↗ MITRE ↗ Advisory ↗ P0 Sheet ↗ CISA KEV ↗

EPSS Score

Source: FIRST.org · 2026-05-24

13.27%

probability

This CVE has a 13.27% probability of being exploited in the next 30 days.

0% Top 94.2th percentile of all CVEs 100%

CVSS score unavailable

Neither CIRCL nor NVD returned a CVSS score for this CVE. View on VulnerabilityLookup ↗

Description

Project Zero

Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability

Attack Intelligence

CWE-118 · Incorrect Access of Indexable Resource ('Range Error') CWE-119 · Buffer Overflow CWE-122 · Heap-based Buffer Overflow CWE-664 · Improper Control of a Resource Through its Lifetime CWE-787 · Out-of-bounds Write CWE-788 · Access of Memory Past End of Buffer

Google Project Zero

Patched

Feb. 11, 2025

Reported by

Anonymous

Root Cause Analysis

???

Microsoft Fixes 78 Flaws, 5 Zero-Days Exploited; CVSS 10 Bug Impacts Azure DevOps Server

TheHackerNews

Microsoft’s Patch Tuesday Fixes 63 Flaws, Including Two Under Active Exploitation

TheHackerNews

Microsoft February 2025 Patch Tuesday fixes 4 zero-days, 55 flaws

BleepingComputer Feb 11, 2025

Microsoft and Adobe Patch Tuesday, February 2025 Security Update Review

Qualys Feb 11, 2025

⚡ THN Weekly Recap: Google Secrets Stolen, Windows Hack, New Crypto Scams and More

TheHackerNews

Signal Intelligence

Confidenceⓘ

82%

EPSS 13.27%

Mentions 5

Last Seen Feb 11, 2025

CNA Information

Analyst Note

CVE-2025-21418 is confirmed as a zero-day elevation of privilege vulnerability in Windows Ancillary Function Driver, tracked by Google Project Zero and patched in Microsoft's February 2025 security update alongside 3 other zero-days. The HIGH CVSS score (7.8) and inclusion in official patch documentation provide strong validation of the vulnerability's authenticity and severity.