Published May 11, 2023Sources checked Oct 29, 2026
9.8CRITICALCVSS out of 10
What this means
Review the available evidence
CVE-2023-24540 and is rated Critical severity with a CVSS score of 9.8. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
What to do next
Remediation and response
Microsoft Security Response Center guidance
Vendor revision: Sep 17, 2026
CBL-Mariner Releases
Vendor-listed releases
1.21.6-1
1.20.11-1
CISA KEVNot listedBased on the latest collected catalog
EPSS1.6%Estimated 30-day exploitation probability
Ransomware useNot markedCISA KEV ransomware field
Threat actors0Source-linked actor relationships
Overview
What is CVE-2023-24540?
Not all valid JavaScript whitespace characters are considered to be whitespace. Templates containing whitespace characters outside of the character set "\t\n\f\r\u0020\u2028\u2029" in JavaScript contexts that also contain actions may not be properly sanitized during execution.