DEBIAN-CVE-2026-91991

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Source

https://security-tracker.debian.org/tracker/CVE-2026-91991

Import Source

https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-91991.json

JSON Data

https://api.test.osv.dev/v1/vulns/DEBIAN-CVE-2026-91991

Upstream

CVE-2026-91991

Published

2026-09-15T16:17:58Z

Modified

2026-09-22T09:00:33Z

Severity

6.3 (Medium) CVSS_V4 - 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 Calculator

Summary

[none]

Details

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

https://security-tracker.debian.org/tracker/CVE-2026-91991

Affected packages

Debian:12 / python-tornado

Package

Name: python-tornado
Purl: pkg:deb/debian/python-tornado?arch=source&distro=bookworm

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Affected versions

6.*

6.2.0-3

6.2.0-3+deb12u1

6.2.0-3+deb12u2

6.2.0-3+deb12u3

6.2.0-3+deb12u4

6.3.2-1

6.4.0-1

6.4.0-2

6.4.1-1

6.4.1-2

6.4.1-3

6.4.2-1

6.4.2-2

6.4.2-3

6.5.2-1

6.5.2-2

6.5.2-3

6.5.4-0.1

6.5.4-1

6.5.5-1

6.5.5-2

6.5.5-3

6.5.5-4

6.5.5-5

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Database specific

source

"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-91991.json"

Debian:14 / python-tornado