CVE-2026-91991

Published: Sep 15, 2026Modified: Oct 8, 2026Deferred

6.3

Vector

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XShow less

Source: disclosure@vulncheck.com (Secondary)

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.

Related CWEs

CWE-113

Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')

The product receives data from an HTTP agent/component (e.g., web server, proxy, browser, etc.), but it does not neutralize or incorrectly neutralizes CR and LF characters before the data is included in outgoing HTTP headers.

References (3)

https://github.com/tornadoweb/tornado/security/advisories/GHSA-wwv5-g3v4-889x

Source: disclosure@vulncheck.com

https://www.vulncheck.com/advisories/tornado-before-6.5.8-cookie-attribute-injection-via-capitalized-kwargs

Source: disclosure@vulncheck.com

https://github.com/tornadoweb/tornado/security/advisories/GHSA-wwv5-g3v4-889x

Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0

Timeline

No history available yet.