Microsoft Windows NULL Pointer Dereference Vulnerability

MEDIUM 6.2EXPLOITED (CISA KEV)CVE-2026-21525 · Published 10/02/2026 · updated 17/06/2026

Microsoft Windows NULL Pointer Dereference Vulnerability. Actively exploited: CISA added this vulnerability to its Known Exploited Vulnerabilities catalog on 10/02/2026. Patch affected systems as an emergency.

In short

CVE-2026-21525 is a MEDIUM (CVSS 6.2) vulnerability.
Exploited in the wild: CISA added it to the KEV catalog on 10/02/2026.
Chance of exploitation in the next 30 days (EPSS): 4.9%, higher than 92.0% of all vulnerabilities.
No patched version is listed yet: follow the vendor's advisory in References.

Package	Affected versions	Patched versions
Windows Microsoft	Versions not published yet (product named by CISA KEV)

Description

Null pointer dereference in Windows Remote Access Connection Manager allows an unauthorized attacker to deny service locally.

References

msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21525 · Vendor Advisory
vicarius.io/vsociety/posts/cve-2026-21525-detection-script-dos-vulnerability-in-windows-remote-access-connection-manager · Third Party Advisory
vicarius.io/vsociety/posts/cve-2026-21525-mitigation-script-dos-vulnerability-in-windows-remote-access-connection-manager · Mitigation
cisa.gov/known-exploited-vulnerabilities-catalog · US Government Resource
CISA KEV · CVE-2026-21525

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