CVE-2025-21406: Microsoft Windows 10 Version 1507 · Use After Free
Affects Microsoft Windows 10 Version 1507Source CVE Database V5
Not known to be exploited · CVSS 8.8 High.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 1.8% chance of exploitation in 30 days – higher than 78% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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 10 Version 1507 | Affected
| Fixed in– |
AI-suggested
- Immediately disable or restrict the Windows Telephony Service on all affected Windows 10 Version 1507 systems, especially those exposed to untrusted networks.
- Implement network-level controls such as firewall rules to block incoming traffic to ports used by the Telephony Service.
- Educate users to avoid interacting with unsolicited telephony requests or calls that could trigger the vulnerability.
- Monitor network and endpoint logs for unusual Telephony Service activity or signs of exploitation attempts.
- Prioritize upgrading or migrating systems from Windows 10 Version 1507 to supported, patched versions of Windows 10 or later.
- Apply any security updates or patches released by Microsoft for this vulnerability as soon as they become available.
- Employ endpoint detection and response (EDR) solutions capable of detecting exploitation behaviors related to use-after-free conditions.
- Conduct regular vulnerability assessments and penetration testing focusing on legacy systems and exposed services.
- Segment networks to isolate legacy systems and limit potential lateral movement in case of compromise.
Description
Windows Telephony Service Remote Code Execution Vulnerability