Skip to main content
VulnerabilityPublished Updated

CVE-2025-21406: Microsoft Windows 10 Version 1507 · Use After Free

Affects Microsoft Windows 10 Version 1507Source CVE Database V5

0

Not known to be exploited · CVSS 8.8 High.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score
8.8High
How severe the flaw is on the 0–10 CVSS scale.
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:C

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 11 Feb 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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

ProductAffectedFixed in
Microsoft Windows 10 Version 1507Affected
  • =10.0.10240.0
Fixed in–

AI-suggested

  1. Immediately disable or restrict the Windows Telephony Service on all affected Windows 10 Version 1507 systems, especially those exposed to untrusted networks.
  2. Implement network-level controls such as firewall rules to block incoming traffic to ports used by the Telephony Service.
  3. Educate users to avoid interacting with unsolicited telephony requests or calls that could trigger the vulnerability.
  4. Monitor network and endpoint logs for unusual Telephony Service activity or signs of exploitation attempts.
  5. Prioritize upgrading or migrating systems from Windows 10 Version 1507 to supported, patched versions of Windows 10 or later.
  6. Apply any security updates or patches released by Microsoft for this vulnerability as soon as they become available.
  7. Employ endpoint detection and response (EDR) solutions capable of detecting exploitation behaviors related to use-after-free conditions.
  8. Conduct regular vulnerability assessments and penetration testing focusing on legacy systems and exposed services.
  9. Segment networks to isolate legacy systems and limit potential lateral movement in case of compromise.

Description

Windows Telephony Service Remote Code Execution Vulnerability

References

Community reviews

Loading reviews…