tornadoweb Tornado up to 6.5.4 Attributes RequestHandler.set_cookie samesite invalid special elements

CVSS Meta Temp Score
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CTI Interest Score
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7.1$0-$5k0.00

Summaryinfo

A vulnerability described as critical has been identified in tornadoweb Tornado up to 6.5.4. This affects the function RequestHandler.set_cookie of the component Attributes Handler. Executing a manipulation of the argument samesite can lead to improper handling of invalid use of special elements. This vulnerability is handled as CVE-2026-35536. The attack can be executed remotely. There is not any exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in tornadoweb Tornado up to 6.5.4. It has been declared as critical. This vulnerability affects the function RequestHandler.set_cookie of the component Attributes Handler. The manipulation of the argument samesite with an unknown input leads to a improper handling of invalid use of special elements vulnerability. The CWE definition for the vulnerability is CWE-159. The product does not properly filter, remove, quote, or otherwise manage the invalid use of special elements in user-controlled input, which could cause adverse effect on its behavior and integrity. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

In Tornado before 6.5.5, cookie attribute injection could occur because the domain, path, and samesite arguments to .RequestHandler.set_cookie were not checked for crafted characters.

The advisory is available at github.com. This vulnerability was named CVE-2026-35536 since 04/03/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Technical details are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 304899 (Linux Distros Unpatched Vulnerability : CVE-2026-35536), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.5.5 eliminates this vulnerability. The upgrade is hosted for download at github.com.

The vulnerability is also documented in the vulnerability database at Tenable (304899). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Vendor

Name

Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.3
VulDB Meta Temp Score: 7.1

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.2
CNA Vector (MITRE): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Improper handling of invalid use of special elements
CWE: CWE-159 / CWE-20
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 304899
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-35536

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Tornado 6.5.5

Timelineinfo

04/03/2026 Advisory disclosed
04/03/2026 +0 days CVE reserved
04/03/2026 +0 days VulDB entry created
04/05/2026 +2 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: GHSA-78cv-mqj4-43f7
Status: Confirmed

CVE: CVE-2026-35536 (🔒)
GCVE (CVE): GCVE-0-2026-35536
GCVE (VulDB): GCVE-100-355066

Entryinfo

Created: 04/03/2026 07:49
Updated: 04/05/2026 10:30
Changes: 04/03/2026 07:49 (67), 04/05/2026 10:30 (2)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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