CVE-2025-9670: Mixmark-Io Turndown

Medium severity, CVSS 5.3. EPSS: 0.5% chance of exploitation in the next 30 days.

A security flaw has been discovered in mixmark-io turndown up to 7.2.1. This affects an unknown function of the file src/commonmark-rules.js. Performing manipulation results in inefficient regular expression complexity. It is possible to initiate the attack remotely. The exploit has been released to the public and may be exploited.

Affected products

• Mixmark-Io Turndown: version 7.2.0 only; version 7.2.1 only

Published 2025-08-29. Last modified 2026-06-17.