CSIRTS // UNIFIED SECURITY ADVISORY FEEDSYS ● ONLINE · POWERED BY INTELFUSIONS.COM

← Back to feed

CVE-2026-21525: Microsoft Windows NULL Pointer Dereference Vulnerability

criticalknown exploitedCVE-2026-21525
Actively exploited. At least one CVE in this advisory is listed in the CISA Known Exploited Vulnerabilities catalog — exploitation has been observed in the wild. Treat remediation as urgent.
Microsoft Windows Remote Access Connection Manager contains a NULL pointer dereference that could allow an unauthorized attacker to deny service locally.

CSIRTS triage

vendor: Microsoftproduct: WindowsDenial of service
What
A NULL pointer dereference could allow an unauthorized attacker to deny service locally.
Who is affected
Deployments of Microsoft Windows Remote Access Connection Manager.
Urgency
Remediation is urgent due to active exploitation and critical severity.
Action
Install the security update from Microsoft.

AI-assisted analysis generated from the source advisory — verify against the original.

⚡ Watch Windows

Get an email when a new Windows advisory drops — max one per day, one-click unsubscribe.

Details

Source
CISA Known Exploited Vulnerabilities (US · database · site)
Severity
critical
Published
2026-02-10
Exploitation
Observed in the wild (CISA KEV)

Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-21525

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Referenced CVEs

CVECSIRTS overviewExternal
CVE-2026-21525coverage & exploitation statusNVD · CVE.org

More from CISA Known Exploited Vulnerabilities