CVE-2026-35536: Tornadoweb Tornado

Medium severity, CVSS 5.3. EPSS: 0.3% chance of exploitation in the next 30 days.

In Tornado before 6.5.5, cookie attribute injection could occur because the domain, path, and samesite arguments to .RequestHandler.set_cookie were not checked for crafted characters.

Affected products

• Tornadoweb Tornado: before 6.5.5 (fixed in 6.5.5)

Published 2026-04-03. Last modified 2026-07-24.