CVE-2021-40449
Exploited in the Wild
✓ Confirmed 0-Day
★ Google Project Zero
Triaged: March 5, 2026
1 article
EPSS Score
Source: FIRST.org · 2026-05-24
91.73%
probability
This CVE has a 91.73% probability
of being exploited in the next 30 days.
0%
Top 99.7th percentile of all CVEs
100%
CVSS score unavailable
Neither CIRCL nor NVD returned a CVSS score for this CVE.
View on VulnerabilityLookup ↗
Description
Project ZeroUse-after-free in Win32k
Attack Intelligence
CWE-118
· Incorrect Access of Indexable Resource ('Range Error')
CWE-119
· Buffer Overflow
CWE-416
· Use After Free
CWE-664
· Improper Control of a Resource Through its Lifetime
CWE-666
· Operation on Resource in Wrong Phase of Lifetime
CWE-672
· Operation on a Resource after Expiration or Release
CWE-825
· Expired Pointer Dereference
Google Project Zero
Patched
Oct. 12, 2021
Reported by
Boris Larin (oct0xor) with Kaspersky
Root Cause Analysis
???
Exploits & PoC
KaLendsi/CVE-2021-40449-Exploit
windows 10 14393 LPE
99
CppXL/cve-2021-40449-poc
PoC CVE-2021-40449 — CppXL/cve-2021-40449-poc
1
toanthang1842002/CVE-2021-40449
PoC CVE-2021-40449 — toanthang1842002/CVE-2021-40449
0
3 repos — triés par ⭐
Rechercher sur GitHub ↗
Chinese hackers use Windows zero-day to attack defense, IT firms
BleepingComputer
Oct 12, 2021
Signal Intelligence
Confidence
95%
EPSS
91.73%
Mentions
1
Last Seen
Oct 12, 2021
CNA Information
Analyst Note
Auto-imported from Google Project Zero — confirmed zero-day by definition.
Threat Actors 10
APT 29
apt_group
Information theft and espionage
🇷🇺 RU
Cobalt
apt_group
Financial crime
🇷🇺 RU
APT 28
apt_group
Information theft and espionage
🇷🇺 RU
Hacking Team
apt_group
🇮🇹 IT
Infy
apt_group
Information theft and espionage
🇮🇷 IR
Earth Lamia
apt_group
Information theft and espionage
🇨🇳 CN
IronHusky
apt_group
Information theft and espionage
🇨🇳 CN
APT 22
apt_group
Information theft and espionage
🇨🇳 CN
Mana Team
apt_group
🇨🇳 CN
Iron Group
apt_group
Information theft and espionage
🇨🇳 CN
Triage Info
Decided atMar 05, 2026