CVE-2025-21350: Microsoft Windows 10 Version 1507 · Improper Input Validation
Affects Microsoft Windows 10 Version 1507Source CVE Database V5
Not known to be exploited · CVSS 5.9 Medium.
Data as of 26 Oct 2026, 09:15 UTC
- EPSS
- 2.1% chance of exploitation in 30 days – higher than 81% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/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
To mitigate CVE-2025-21350, European organizations should prioritize upgrading affected systems from Windows 10 Version 1507 to a supported and patched Windows 10 release or later Windows versions where the vulnerability is addressed. Since no direct patches are currently linked, system upgrades are the most effective mitigation. Organizations should inventory their environments to identify any legacy systems still running the vulnerable build and plan for their timely replacement or upgrade. Network-level mitigations include restricting access to Kerberos ports (typically TCP/UDP 88) from untrusted networks and implementing network segmentation to limit exposure. Monitoring for unusual Kerberos service crashes or authentication failures can provide early detection of exploitation attempts. Additionally, organizations should ensure robust backup and recovery procedures to minimize downtime in case of service disruption. Security teams should stay informed about updates from Microsoft regarding patches or workarounds. Finally, enforcing strict input validation and anomaly detection on authentication traffic through advanced security appliances or endpoint protection platforms may help detect or block malformed Kerberos requests attempting to exploit this vulnerability.
Description
Windows Kerberos Denial of Service Vulnerability