Back to vendor advisories
Ubuntu Security NoticesUSN-8952-3

USN-8952-3: Tornado regression

Severity not listed 6 CVEs Published Nov 11, 2026 at 8:15 AM UTC

Summary

USN-8952-2 fixed a regression in Tornado that broke static file serving for applications that subclass Tornado's StaticFileHandler, such as Jupyter. Unfortunately, that update's incomplete fix could introduce a regression by rejecting symlinks into system directories like /usr/share, which distribution packages use for their JavaScript and fonts, causing web UIs to return 403 errors. This update fixes the problem.

We apologize for the inconvenience.

Original advisory details:

It was discovered that Tornado did not properly handle certain HTTP requests and network inputs. An attacker could possibly use these issues to cause a denial of service, expose sensitive information, or bypass access controls.

(CVE-2023-54397, CVE-2024-14029, CVE-2026-91990, CVE-2026-91992, CVE-2026-103262, CVE-2026-103263)

Products covered

A separate affected-products list was not included in the collected bulletin.

Remediation

Separate remediation guidance was not included in the collected bulletin.

CVEs in this advisory 6

Updates

  1. Published by Ubuntu

    The publication date reported by the vendor.

  2. Added to SecurityAlert

    We collected the advisory from the official source.

  3. Confirmed at the source

    Our collector saw this advisory during a later source check.