VDB-341563 · CVE-2025-14822 · WID-SEC-2025-2880

Mattermost up to 10.11.8/11.1.x HTTP Request algorithmic complexity

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 was found in Mattermost up to 10.11.8/11.1.x. It has been classified as problematic. This affects an unknown part of the component HTTP Request Handler. This manipulation causes algorithmic complexity. This vulnerability appears as CVE-2025-14822. The attack may be initiated remotely. There is no available exploit. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability has been found in Mattermost up to 10.11.8/11.1.x and classified as problematic. Affected by this vulnerability is an unknown code block of the component HTTP Request Handler. The manipulation with an unknown input leads to a algorithmic complexity vulnerability. The CWE definition for the vulnerability is CWE-407. An algorithm in a product has an inefficient worst-case computational complexity that may be detrimental to system performance and can be triggered by an attacker, typically using crafted manipulations that ensure that the worst case is being reached. As an impact it is known to affect availability. The summary by CVE is:

Mattermost versions 10.11.x <= 10.11.8 fail to validate input size before processing hashtags which allows an authenticated attacker to exhaust CPU resources via a single HTTP request containing a post with thousands space-separated tokens

The weakness was presented by CatenaCyber. It is possible to read the advisory at mattermost.com. This vulnerability is known as CVE-2025-14822 since 12/17/2025. The exploitation appears to be difficult. The attack can be launched remotely. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

Upgrading to version 10.11.9 or 11.2.0 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2025-2880). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

Mattermost Mattermost

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: 4.2
VulDB Meta Temp Score: 4.2

VulDB Base Score: 3.1
VulDB Temp Score: 3.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 6.5
NVD Vector: 🔒

CNA Base Score: 3.1
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: Algorithmic complexity
CWE: CWE-407 / 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 10.11.9/11.2.0

Timelineinfo

12/17/2025 CVE reserved
01/16/2026 +30 days Advisory disclosed
01/16/2026 +0 days VulDB entry created
02/27/2026 +42 days VulDB entry last update

Sourcesinfo

Advisory: mattermost.com
Researcher: CatenaCyber
Status: Confirmed

CVE: CVE-2025-14822 (🔒)
GCVE (CVE): GCVE-0-2025-14822
GCVE (VulDB): GCVE-100-341563
CERT Bund: WID-SEC-2025-2880 - Mattermost Server und Desktop: Mehrere Schwachstellen

Entryinfo

Created: 01/16/2026 10:49
Updated: 02/27/2026 11:34
Changes: 01/16/2026 10:49 (65), 01/21/2026 06:53 (11), 02/27/2026 11:34 (7)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.