CVE-2026-91991
Published: September 18, 2026Last modified: October 6, 2026
Description
Tornado before 6.5.8 contains an incomplete fix for cookie attribute injection that allows attackers to inject arbitrary cookie attributes by passing capitalized or legacy keyword arguments to set_cookie. Attackers can embed semicolon-delimited data in capitalized parameters like Domain, Path, or SameSite to bypass validation and modify cookie security attributes.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 5.4 |
| Attack Vector | NETWORK |
| Attack complexity | HIGH |
| Privileges required | NONE |
| User interaction | NONE |
| Scope | CHANGED |
| Confidentiality | LOW |
| Integrity impact | LOW |
| Availability impact | NONE |
| Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 25 LTS | py3-tornado | Fixed (6.5.10-r0) |
| Stream | py3-tornado | Fixed (6.5.10-r0) |