Published Aug 10, 2026Sources checked Oct 28, 2026
2.4LOWCVSS out of 10
What this means
Review the available evidence
CVE-2026-18503 and is rated Low severity with a CVSS score of 2.4. 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: Aug 23, 2026
CBL-Mariner Releases
Vendor-listed releases
3.12.14-1
CISA KEVNot listedBased on the latest collected catalog
EPSS0.1%Estimated 30-day exploitation probability
Ransomware useNot markedCISA KEV ransomware field
Threat actors0Source-linked actor relationships
Overview
What is CVE-2026-18503?
Attacker-controlled CSV samples can trigger super-linear regular-expression work during dialect sniffing and consume significant CPU when applications pass unbounded input to csv.Sniffer.sniff().