CVE-2026-91991

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.

CVSS v3 5.4 MEDIUM

5.4^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.2 / Impact : 2.7

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope CHANGED

References

Link	Resource
https://github.com/tornadoweb/tornado/security/advisories/GHSA-wwv5-g3v4-889x
https://www.vulncheck.com/advisories/tornado-before-6.5.8-cookie-attribute-injection-via-capitalized-kwargs
https://github.com/tornadoweb/tornado/security/advisories/GHSA-wwv5-g3v4-889x

Configurations

No configuration.

History

21 Sep 2026, 20:17

Type	Values Removed	Values Added
References	~~() https://github.com/tornadoweb/tornado/security/advisories/GHSA-wwv5-g3v4-889x -~~	() https://github.com/tornadoweb/tornado/security/advisories/GHSA-wwv5-g3v4-889x -

Information

Published : 2026-09-15 16:17

Updated : 2026-10-08 16:17

NVD link : CVE-2026-91991

Mitre link : CVE-2026-91991

CVE.ORG link : CVE-2026-91991

JSON object : View

Products Affected

No product.

CWE

CWE-113

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

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