CVE-2026-35536: Tornado has cookie attribute injection via .RequestHandler.set_cookie

April 3, 2026 (updated April 4, 2026)

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.

References

github.com/advisories/GHSA-fqwm-6jpj-5wxc
github.com/tornadoweb/tornado
github.com/tornadoweb/tornado/releases/tag/v6.5.5
github.com/tornadoweb/tornado/security/advisories/GHSA-78cv-mqj4-43f7
nvd.nist.gov/vuln/detail/CVE-2026-35536

Code Behaviors & Features

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