CVE-2025-21183: Microsoft Windows 11 Version 24H2 · Double Free
Affects Microsoft Windows 11 Version 24H2Source CVE Database V5
Not known to be exploited · CVSS 7.4 High.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 44% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:CExploitation evidence
Disclosed: evidence found.
CVE published 11 Feb 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Microsoft Windows 11 Version 24H2 | Affected
| Fixed in– |
AI-suggested
- Monitor Microsoft security advisories closely and apply official patches immediately once released.
- Restrict local access to systems running Windows 11 Version 24H2, especially those using ReFS deduplication, by enforcing strict access controls and limiting administrative privileges.
- Disable or limit the use of ReFS deduplication service if feasible until patches are available, particularly on high-risk or critical systems.
- Employ endpoint detection and response (EDR) solutions to monitor for suspicious local privilege escalation attempts and anomalous memory corruption behaviors.
- Conduct regular system audits to identify unauthorized local users or processes that could exploit this vulnerability.
- Use application whitelisting and privilege management to reduce the risk of local code execution by untrusted users.
- Educate IT staff about the vulnerability and ensure incident response plans include scenarios involving local privilege escalation.
- Consider network segmentation to isolate critical Windows 11 24H2 systems to minimize lateral movement opportunities.
Description
Windows Resilient File System (ReFS) Deduplication Service Elevation of Privilege Vulnerability