Mattermost up to 10.5.12/10.11.4/10.12.1/11.0.3 OpenID Connect Authentication incorrect implementation of authentication algorithm

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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7.9$0-$5k0.00

Summaryinfo

A vulnerability, which was classified as critical, was found in Mattermost up to 10.5.12/10.11.4/10.12.1/11.0.3. Affected is an unknown function of the component OpenID Connect Authentication. Executing a manipulation can lead to incorrect implementation of authentication algorithm. This vulnerability is handled as CVE-2025-12419. The attack can be executed remotely. There is not any exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability has been found in Mattermost up to 10.5.12/10.11.4/10.12.1/11.0.3 and classified as critical. This vulnerability affects some unknown functionality of the component OpenID Connect Authentication. The manipulation with an unknown input leads to a incorrect implementation of authentication algorithm vulnerability. The CWE definition for the vulnerability is CWE-303. The requirements for the product dictate the use of an established authentication algorithm, but the implementation of the algorithm is incorrect. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

Mattermost versions 10.12.x <= 10.12.1, 10.11.x <= 10.11.4, 10.5.x <= 10.5.12, 11.0.x <= 11.0.3 fail to properly validate OAuth state tokens during OpenID Connect authentication which allows an authenticated attacker with team creation privileges to take over a user account via manipulation of authentication data during the OAuth completion flow. This requires email verification to be disabled (default: disabled), OAuth/OpenID Connect to be enabled, and the attacker to control two users in the SSO system with one of them never having logged into Mattermost.

The weakness was released by daw10. The advisory is available at mattermost.com. This vulnerability was named CVE-2025-12419 since 10/28/2025. The exploitation appears to be easy. The attack can be initiated remotely. The technical details are unknown and an exploit is not available.

The vulnerability scanner Nessus provides a plugin with the ID 278110 (Mattermost Server 10.5.x <= 10.5.12 / 10.11.x <= 10.11.4 / 10.12.x <= 10.12.1 / 11.0.x <= 11.0.3 Improper Authentication (MMSA-2025-00547)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 10.5.13, 10.11.5, 10.12.2, 11.0.4 or 11.1.0 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (278110), EUVD (EUVD-2025-199827) and CERT Bund (WID-SEC-2025-2434). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

  • Mattermost Mattermost

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.1
VulDB Meta Temp Score: 7.9

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

CNA Base Score: 9.9
CNA Vector (Mattermost): 🔒

CVSSv2info

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

Exploitinginfo

Class: Incorrect implementation of authentication algorithm
CWE: CWE-303
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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Nessus ID: 278110
Nessus Name: Mattermost Server 10.5.x <= 10.5.12 / 10.11.x <= 10.11.4 / 10.12.x <= 10.12.1 / 11.0.x <= 11.0.3 Improper Authentication (MMSA-2025-00547)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Mattermost 10.5.13/10.11.5/10.12.2/11.0.4/11.1.0

Timelineinfo

10/28/2025 CVE reserved
11/27/2025 +30 days Advisory disclosed
11/27/2025 +0 days VulDB entry created
12/11/2025 +14 days VulDB entry last update

Sourcesinfo

Advisory: mattermost.com
Researcher: daw10
Status: Confirmed

CVE: CVE-2025-12419 (🔒)
GCVE (CVE): GCVE-0-2025-12419
GCVE (VulDB): GCVE-100-333706
EUVD: 🔒
CERT Bund: WID-SEC-2025-2434 - Mattermost Server: Mehrere Schwachstellen erm&ouml;glichen die Umgehung von Sicherheitsma&szlig;nahmen

Entryinfo

Created: 11/27/2025 17:54
Updated: 12/11/2025 01:49
Changes: 11/27/2025 17:54 (64), 11/27/2025 19:15 (1), 11/27/2025 19:23 (1), 11/28/2025 16:00 (7), 12/11/2025 01:49 (2)
Complete: 🔍
Cache ID: 216::103

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

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