CVE-2025-21407: Microsoft Windows 10 Version 1507 · Heap-based Buffer Overflow
Affects Microsoft Windows 10 Version 1507Source CVE Database V5
Not known to be exploited · CVSS 8.8 High.
Data as of 26 Oct 2026, 07:57 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 2026-10-26.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Microsoft Windows 10 Version 1507 | Affected
| Fixed in– |
AI-suggested
Given the absence of an official patch, organizations should prioritize upgrading from Windows 10 Version 1507 to a supported and fully patched Windows version to eliminate exposure. If immediate upgrade is not feasible, organizations should disable or restrict the Windows Telephony Service to prevent remote access, especially on systems exposed to untrusted networks. Network-level controls such as firewall rules should block inbound traffic targeting telephony service ports. Employ endpoint detection and response (EDR) solutions to monitor for anomalous behavior related to telephony service processes. User education to avoid interacting with suspicious telephony prompts can reduce exploitation likelihood. Regularly audit systems to identify and remediate legacy Windows 10 installations. Once a patch is released, apply it promptly. Additionally, implement network segmentation to isolate vulnerable systems and reduce lateral movement opportunities. Maintain up-to-date backups to recover from potential compromise.
Description
Windows Telephony Service Remote Code Execution Vulnerability