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.
5.7	$0-$5k	0.00

Summaryinfo

A vulnerability described as critical has been identified in Mattermost up to 9.11.8/10.3.3/10.4.2. This vulnerability affects unknown code of the component Channel Conversion Handler. Such manipulation leads to authorization. This vulnerability is listed as CVE-2025-27933. The attack may be performed from remote. There is no available exploit. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Mattermost up to 9.11.8/10.3.3/10.4.2 and classified as critical. Affected by this issue is an unknown code block of the component Channel Conversion Handler. The manipulation with an unknown input leads to a authorization vulnerability. Using CWE to declare the problem leads to CWE-863. The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. This allows attackers to bypass intended access restrictions. Impacted is confidentiality, integrity, and availability. CVE summarizes:

Mattermost versions 10.4.x <= 10.4.2, 10.3.x <= 10.3.3, 9.11.x <= 9.11.8 fail to fail to enforce channel conversion restrictions, which allows members with permission to convert public channels to private ones to also convert private ones to public

The weakness was presented by mrhashimamin. The advisory is available at mattermost.com. This vulnerability is handled as CVE-2025-27933 since 03/20/2025. The exploitation is known to be easy. The attack may be launched remotely. The technical details are unknown and an exploit is not available.

The vulnerability scanner Nessus provides a plugin with the ID 233453 (Mattermost Server 9.11.x < 9.11.9 / 10.3.x < 10.3.4 / 10.4.x < 10.4.3 (MMSA-2025-00418)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 9.11.9, 10.3.4, 10.4.3 or 10.5.0 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (233453). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

• Groupware Software

Name

• Mattermost

Version

• 9.11.0
• 9.11.1
• 9.11.2
• 9.11.3
• 9.11.4
• 9.11.5
• 9.11.6
• 9.11.7
• 9.11.8
• 10.3.0
• 10.3.1
• 10.3.2
• 10.3.3
• 10.4.0
• 10.4.1
• 10.4.2

License

• open-source

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.9
VulDB Meta Temp Score: 5.7

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔍
VulDB Reliability: 🔍

CNA Base Score: 5.4
CNA Vector (Mattermost): 🔍

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: Authorization
CWE: CWE-863 / CWE-285 / 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

Nessus ID: 233453
Nessus Name: Mattermost Server 9.11.x < 9.11.9 / 10.3.x < 10.3.4 / 10.4.x < 10.4.3 (MMSA-2025-00418)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Mattermost 9.11.9/10.3.4/10.4.3/10.5.0

Timelineinfo

03/20/2025 🔍
03/21/2025 +1 days 🔍
03/21/2025 +0 days 🔍
03/28/2025 +7 days 🔍

Sourcesinfo

Advisory: mattermost.com
Researcher: mrhashimamin
Status: Confirmed

CVE: CVE-2025-27933 (🔍)
GCVE (CVE): GCVE-0-2025-27933
GCVE (VulDB): GCVE-100-300578

Entryinfo

Created: 03/21/2025 09:59
Updated: 03/28/2025 23:01
Changes: 03/21/2025 09:59 (64), 03/28/2025 23:01 (2)
Complete: 🔍
Cache ID: 216:4CB:103

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