Mattermost up to 10.11.13/11.4.3/11.5.1 API create_post authorization

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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4.2$0-$5k0.00

Summaryinfo

A vulnerability identified as problematic has been detected in Mattermost up to 10.11.13/11.4.3/11.5.1. This affects the function create_post of the component API. Performing a manipulation results in authorization. This vulnerability was named CVE-2026-3637. The attack may be initiated remotely. There is no available exploit. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Mattermost up to 10.11.13/11.4.3/11.5.1. It has been classified as problematic. This affects the function create_post of the component API. The manipulation with an unknown input leads to a authorization vulnerability. CWE is classifying the issue as CWE-862. The product does not perform an authorization check when an actor attempts to access a resource or perform an action. This is going to have an impact on integrity. The summary by CVE is:

Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to check the create_post channel permission during post edit operations which allows an authenticated attacker with revoked posting privileges to modify their existing posts via direct API requests to the post update and patch endpoints.. Mattermost Advisory ID: MMSA-2026-00627

The weakness was presented by 0x7oda7123. It is possible to read the advisory at mattermost.com. This vulnerability is uniquely identified as CVE-2026-3637 since 03/06/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 10.11.14, 11.4.4, 11.5.2 or 11.6.0 eliminates this vulnerability.

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

Productinfo

Type

Name

Version

License

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

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

Exploitinginfo

Class: Authorization
CWE: CWE-862 / CWE-863 / CWE-285
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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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Mattermost 10.11.14/11.4.4/11.5.2/11.6.0

Timelineinfo

03/06/2026 CVE reserved
05/18/2026 +72 days Advisory disclosed
05/18/2026 +0 days VulDB entry created
05/18/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: mattermost.com
Researcher: 0x7oda7123
Status: Confirmed

CVE: CVE-2026-3637 (🔒)
GCVE (CVE): GCVE-0-2026-3637
GCVE (VulDB): GCVE-100-364443

Entryinfo

Created: 05/18/2026 10:01
Changes: 05/18/2026 10:01 (65)
Complete: 🔍
Cache ID: 216::103

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