CVE-2026-18503

Name of the Vulnerable Software and Affected Versions Python (affected versions not specified)

Description Attacker-controlled CSV samples can trigger super-linear regular-expression work during dialect sniffing, leading to significant CPU consumption when applications pass unbounded input to the csv.Sniffer.sniff() function. Super-linear regular-expression work refers to a condition where the time taken to process a string increases disproportionately to the length of the input, potentially causing a denial of service.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability. As a temporary workaround, avoid passing unbounded input to the csv.Sniffer.sniff() function.