What is GHSA-jj9x-pjq2-f55m?

GHSA-jj9x-pjq2-f55m is a security advisory published by GitHub Security Advisories with Medium severity. Tornado before 6.5.8 contains an incomplete fix for cookie attribute injection that allows...

Which CVE IDs does GHSA-jj9x-pjq2-f55m cover?

GHSA-jj9x-pjq2-f55m covers the following CVE IDs: CVE-2026-91991. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of GHSA-jj9x-pjq2-f55m?

GHSA-jj9x-pjq2-f55m has a CVSS v3 base score of 5.4, published by GitHub Security Advisories.

GHSA-jj9x-pjq2-f55mMediumCVSS 5.4

Tornado before 6.5.8 contains an incomplete fix for cookie attribute injection that allows...

Vendor

GitHub Security Advisories

Published

September 15, 2026

Last Modified

September 15, 2026

🔗 CVE IDs covered (1)

CVE-2026-91991 →

📋 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.

🔗 References (4)

https://github.com/tornadoweb/tornado/security/advisories/GHSA-wwv5-g3v4-889x
https://nvd.nist.gov/vuln/detail/CVE-2026-91991
https://www.vulncheck.com/advisories/tornado-before-6.5.8-cookie-attribute-injection-via-capitalized-kwargs
https://github.com/advisories/GHSA-jj9x-pjq2-f55m