VDB-365132 · CVE-2026-9053 · EUVD-2026-31401

9front HTML File unrestricted upload

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
7.0	$0-$5k	0.00

Summaryinfo

A vulnerability described as critical has been identified in 9front. This impacts an unknown function of the component HTML File Handler. Such manipulation leads to unrestricted upload. This vulnerability is uniquely identified as CVE-2026-9053. The attack can be launched remotely. No exploit exists. It is advisable to implement a patch to correct this issue.

Detailsinfo

A vulnerability, which was classified as critical, has been found in 9front (unknown version). Affected by this issue is an unknown code block of the component HTML File Handler. The manipulation with an unknown input leads to a unrestricted upload vulnerability. Using CWE to declare the problem leads to CWE-434. The product allows the attacker to upload or transfer files of dangerous types that can be automatically processed within the product's environment. Impacted is confidentiality, integrity, and availability. CVE summarizes:

Mothra would respect a default value given by a website for HTML file upload forms. An attacker could craft a website with a malicious default file path, and then conceal this form element.

The weakness was disclosed by Kristo. The advisory is shared for download at git.9front.org. This vulnerability is handled as CVE-2026-9053 since 05/19/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1608.002.

Applying the patch d145acc9ef0da47131af6ad94e87264e04870d47 is able to eliminate this problem. The bugfix is ready for download at git.9front.org.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-31401). Once again VulDB remains the best source for vulnerability data.

Productinfo

Name

9front

CPE 2.3info

🔒

CPE 2.2info

🔒

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 7.3
VulDB Meta Temp Score: 7.0

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

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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

Exploitinginfo

Class: Unrestricted upload
CWE: CWE-434 / CWE-284 / CWE-266
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔒

Patch: d145acc9ef0da47131af6ad94e87264e04870d47

Timelineinfo

05/19/2026 CVE reserved
05/22/2026 +3 days Advisory disclosed
05/22/2026 +0 days VulDB entry created
05/24/2026 +2 days VulDB entry last update

Sourcesinfo

Advisory: git.9front.org
Researcher: Kristo
Status: Confirmed

CVE: CVE-2026-9053 (🔒)
GCVE (CVE): GCVE-0-2026-9053
GCVE (VulDB): GCVE-100-365132
EUVD: 🔒

Entryinfo

Created: 05/22/2026 06:24
Updated: 05/24/2026 07:54
Changes: 05/22/2026 06:24 (71), 05/22/2026 07:16 (1), 05/24/2026 07:54 (1)
Complete: 🔍
Cache ID: 216::103