VDB-351242 · CVE-2026-26246 · GCVE-0-2026-26246

Mattermost up to 10.11.10/11.2.2/11.3.0 PSD File Parser memory allocation

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.
4.2	$0-$5k	0.00

Summaryinfo

A vulnerability labeled as problematic has been found in Mattermost up to 10.11.10/11.2.2/11.3.0. Affected by this issue is some unknown functionality of the component PSD File Parser. Such manipulation leads to memory allocation. This vulnerability is uniquely identified as CVE-2026-26246. The attack can be launched remotely. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Mattermost up to 10.11.10/11.2.2/11.3.0. It has been rated as problematic. Affected by this issue is an unknown part of the component PSD File Parser. The manipulation with an unknown input leads to a memory allocation vulnerability. Using CWE to declare the problem leads to CWE-789. The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated. Impacted is availability. CVE summarizes:

Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to bound memory allocation when processing PSD image files which allows an authenticated attacker to cause server memory exhaustion and denial of service via uploading a specially crafted PSD file. Mattermost Advisory ID: MMSA-2026-00572

The weakness was disclosed by Juho Forsén. The advisory is available at mattermost.com. This vulnerability is handled as CVE-2026-26246 since 02/13/2026. The exploitation is known to be easy. The attack may be launched remotely. The technical details are unknown and an exploit is not available.

Upgrading to version 10.11.11, 11.2.3, 11.3.1 or 11.4.0 eliminates this vulnerability.

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

Productinfo

Type

Groupware Software

Name

Mattermost

Version

License

open-source

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.3
VulDB Meta Temp Score: 4.2

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 4.3
CNA Vector (Mattermost): 🔒

CVSSv2info

AV	AC	Au	C	I	A
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💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Memory allocation
CWE: CWE-789 / CWE-400 / CWE-404
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: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Mattermost 10.11.11/11.2.3/11.3.1/11.4.0

Timelineinfo

02/13/2026 CVE reserved
03/16/2026 +31 days Advisory disclosed
03/16/2026 +0 days VulDB entry created
03/20/2026 +4 days VulDB entry last update

Sourcesinfo

Advisory: mattermost.com
Researcher: Juho Forsén
Status: Confirmed

CVE: CVE-2026-26246 (🔒)
GCVE (CVE): GCVE-0-2026-26246
GCVE (VulDB): GCVE-100-351242

Entryinfo

Created: 03/16/2026 14:49
Updated: 03/20/2026 23:04
Changes: 03/16/2026 14:49 (65), 03/20/2026 23:04 (1)
Complete: 🔍
Cache ID: 216::103