Quick answers
- Is CVE-2026-116578 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-116578 being exploited in the wild.
- How severe is CVE-2026-116578?
- Medium severity, with a CVSS score of 4, published 26 October 2026.
- Which products and versions are affected?
- tornado (PyPI) < 6.6, ECOSYSTEM:introduced=0,fixed=6.6; Tornado Project Tornado prior to 6.6.
- Is there a fix for CVE-2026-116578?
- Yes. tornado (PyPI): upgrade to 6.6 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-116578 attacked?
- It is attacked over the network.
- Am I affected by CVE-2026-116578?
- Check whether you run tornado (PyPI) or Tornado Project Tornado at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- tornado (PyPI): upgrade to 6.6 or later
pip install "tornado>=6.6"
Technical details
RedirectHandler URL templates perform regex-capture substitutions that can alter the redirect target's scheme or network location when substitutions appear at specific positions (start of path, after a fixed host, or at template beginning). An attacker crafts request paths to inject protocol-relative, absolute, or other URL variants interpreted by browsers as external destinations, resulting in an open redirect. The fix blocks redirects to protocol-relative URLs unless the double-slash pattern was explicitly configured.
Affected products
- Tornado Project Tornado prior to 6.6
Identifiers
- CVE-2026-116578
- GHSA-pw9p-v7r6-gx4p
Timeline
- 2026-10-26: disclosed