MediumVulnerabilityCVE-2026-116577updated 31 Oct 2026, 02:24 UTC

Tornado: Quadratic CPU usage when parsing HTTP headers with line folding

Fixed in tornado 6.6Official, 2 sources

Severity	MediumCVSS 5.3 of 10
Being exploited?	UnclearNo reports either way yet
Fix available?	Yestornado 6.6 · since 28 Oct 2026
How sure is this?	Official, 2 sourcesBacked by an official source

Are you affected?

Package / product	Affected versions	Fixed in
tornado · pip	< 6.6	6.6

Timeline

26 Oct 2026, 21:18 UTC
Publicly disclosed
28 Oct 2026, 22:43 UTC
Reported by GitHub Advisory · GitHub Advisory
28 Oct 2026, 22:44 UTC
Picked up by Zero Radar
31 Oct 2026, 02:24 UTC
NVD reported on it · NVD

Sources 2 reports, oldest first

Official vendor, government CERT or advisory database

Technical details

ID: CVE-2026-116577 · GHSA-pcg2-g6cj-q92c
CVSS: 5.3 / 10
EPSS: 0.4% chance of exploitation within 30 days
Disclosed: 26 Oct 2026, 21:18 UTC
On Zero Radar: 28 Oct 2026, 22:44 UTC (2 days after disclosure)
Last change: 31 Oct 2026, 02:24 UTC

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Tornado: Quadratic CPU usage when parsing HTTP headers with line folding · Zero Radar