CRITICAL · CVSS 9.8 CISA Known Exploited Vulnerability

CVE-2026-33824

Microsoft Internet Key Exchange (IKE) Service Extensions Double Free Vulnerability

Microsoft Internet Key Exchange (IKE) Service Extensions

Double free in Windows IKE Extension allows an unauthorized attacker to execute code over a network.

CVSS
9.8
CRITICAL
EPSS
72.7%
30-day exploitation
Ransomware groups
0
recorded exploiting
Published
14 Apr 2026
CWE-415

Exploitation status

CISA Known Exploited Vulnerabilities

Listed by CISA on 18 August 2026. US federal agencies were required to remediate it by 21 August 2026.

EPSS — exploitation probability

FIRST puts the probability of exploitation activity in the next 30 days at 72.7%, which is higher than 99.4% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Frequently asked questions

Is CVE-2026-33824 being exploited by ransomware groups?

No ransomware group in this database is currently recorded as exploiting CVE-2026-33824.

What does CVE-2026-33824 affect?

CVE-2026-33824 affects Microsoft Internet Key Exchange (IKE) Service Extensions. Double free in Windows IKE Extension allows an unauthorized attacker to execute code over a network.

How severe is CVE-2026-33824?

CVE-2026-33824 is rated CRITICAL with a CVSS base score of 9.8. EPSS puts the probability of exploitation in the next 30 days at 72.7%, higher than 99.4% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 21 August 2026.

How should organisations respond to CVE-2026-33824?

Apply the vendor patch for Microsoft Internet Key Exchange (IKE) Service Extensions as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.