CVE-2026-21510

ENISA EUVD: EUVD-2026-7337 ↗
Exploited in the Wild ✓ Confirmed 0-Day ★ Google Project Zero
Triaged: Feb. 18, 2026 10 articles
VulnLookup ↗ NVD ↗ EUVD ↗ MITRE ↗ Advisory ↗ P0 Sheet ↗ CISA KEV ↗

EPSS Score

Source: FIRST.org · 2026-05-24
4.96%
probability
This CVE has a 4.96% probability of being exploited in the next 30 days.
0% Top 89.8th percentile of all CVEs 100%

CVSS v3.1

Source: NVD
8.8
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Temporal
Exploit Code Maturity
Functional
Remediation Level
Official Fix
Report Confidence
Confirmed
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C

Description

Project Zero
Microsoft Office Security Feature Bypass Vulnerability

Affected Products

Google Project Zero

Patched
Feb. 10, 2026
Reported by
Google Threat Intelligence Group, Microsoft Threat Intelligence Center (MSTIC), Microsoft Security Response Center (MSRC), and Office Product Group Security Team

Signal Intelligence

Confidenceⓘ
92%
EPSS 4.96%
CVSS v3.1 8.8
Mentions 10
Last Seen May 27, 2026

CNA Information

Analyst Note

CVE-2026-21510 is confirmed as a zero-day with high credibility: it appears in Google Project Zero, is documented across multiple reputable security sources (Tenable, BleepingComputer, TheHackerNews, CISA), and was patched by Microsoft in their February 2026 Patch Tuesday addressing six actively exploited zero-days. The HIGH CVSS score (8.8) and protection mechanism bypass nature align with the serious threat level documented in security advisories.

Threat Actors 2

Ice Fog
apt_group Information theft and espionage 🇨🇳 CN
Nomad Panda
apt_group Information theft and espionage 🇨🇳 CN

Triage Info

Decided atFeb 18, 2026