Exploited vulnerabilities / CVE-2026-21525
Confirmed exploited · exploited vulnerability · Microsoft WindowsCVE-2026-21525
Microsoft Windows exploited vulnerability, confirmed exploited in the wild.
Microsoft Windows Remote Access Connection Manager contains a NULL pointer dereference that could allow an unauthorized attacker to deny service locally.
| CISA's name for it | Microsoft Windows NULL Pointer Dereference Vulnerability |
|---|---|
| Vendor and product | Microsoft · Windows |
| Type | exploited vulnerability · CWE-476 |
| Exploited | Confirmed by CISA listed 10 February 2026 |
| Likelihood | more likely to be exploited than most |
| Deadline | 3 March 2026 · already passed |
| Used in ransomware | Not reported |
| Advisories | msrc.microsoft.com ↗ · nvd.nist.gov ↗ |
Three steps, in this order
Apply the vendor's fix or mitigation; CISA lists only vulnerabilities seen exploited.
If you cannot patch now, restrict network access to the affected product.
Check for signs of compromise since the date it was added to the list.
| CISA's required action | Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. |
|---|
Know before someone else finds it
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CVE-2026-21525 in short
Is CVE-2026-21525 being exploited?
Yes. CISA added CVE-2026-21525 to its Known Exploited Vulnerabilities catalogue on 10 February 2026, which it does only on evidence of exploitation in the wild.
What is the CISA deadline for CVE-2026-21525?
US federal agencies must remediate it by 3 March 2026. Everyone else should treat that date as the latest safe point to patch an internet-facing system.
How likely is CVE-2026-21525 to be exploited in the next 30 days?
FIRST's Exploit Prediction Scoring System gives it 5.0%, the 92nd percentile of every CVE it scores.
How do I fix CVE-2026-21525?
Apply the vendor's fix or mitigation; CISA lists only vulnerabilities seen exploited. If you cannot patch now, restrict network access to the affected product. Check for signs of compromise since the date it was added to the list.
Other Microsoft vulnerabilities being exploited
| CVE | Product | Type | Listed |
|---|---|---|---|
| CVE-2026-124194 | Office | exploited vulnerability | 10 November 2026 |
| CVE-2026-96951 | Windows | command injection | 13 October 2026 |
| CVE-2026-65660 | SharePoint | exploited vulnerability | 25 September 2026 |
| CVE-2026-81963 | Windows | privilege escalation | 8 September 2026 |
| CVE-2026-85880 | Windows | privilege escalation | 8 September 2026 |
| CVE-2019-1068 | SQL Server | remote code execution | 26 August 2026 |
Sources: CISA Known Exploited Vulnerabilities catalogue (released 10 November 2026) and FIRST EPSS. Page compiled automatically by SAK T.L.M, the threat-intelligence tool of SAK T.E.C, on 13 November 2026.