Published Nov 12, 2026Sources checked Nov 12, 2026
5.3MEDIUMCVSS out of 10
What this means
Review the available evidence
CVE-2026-126193 and is rated Medium severity with a CVSS score of 5.3. 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: Nov 13, 2026
Release Notes
CISA KEVNot listedBased on the latest collected catalog
EPSSUnavailableNo current score collected
Ransomware useNot markedCISA KEV ransomware field
Threat actors0Source-linked actor relationships
Overview
What is CVE-2026-126193?
Soup Sieve is a CSS selector library for Beautiful Soup. From 0.4 until 3.0, deeply nested CSS pseudo-class selectors can cause recursive parsing to exceed Python’s recursion limit and raise RecursionError .
Applications accepting untrusted selectors may experience failure of the affected request or task if the exception is not handled. The demonstrated behavior is recoverable and does not establish an interpreter crash or persistent service-wide denial of service.