Mattermost up to 10.5.9 OAuth redirect

CVSS Meta Temp Score
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CTI Interest Score
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4.1$0-$5k0.00

Summaryinfo

A vulnerability marked as problematic has been reported in Mattermost up to 10.5.9. The affected element is an unknown function of the component OAuth Handler. Performing a manipulation results in redirect. This vulnerability is identified as CVE-2025-9084. The attack can be initiated remotely. There is not any exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic has been found in Mattermost up to 10.5.9. This affects an unknown code of the component OAuth Handler. The manipulation with an unknown input leads to a redirect vulnerability. CWE is classifying the issue as CWE-601. A web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a Redirect. This simplifies phishing attacks. This is going to have an impact on integrity. The summary by CVE is:

Mattermost versions 10.5.x <= 10.5.9 fail to properly validate redirect URLs which allows attackers to redirect users to malicious sites via crafted OAuth login URLs

The weakness was released by Juho Forsén. The advisory is shared at mattermost.com. This vulnerability is uniquely identified as CVE-2025-9084 since 08/15/2025. The exploitability is told to be difficult. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1204.001 for this issue.

The vulnerability scanner Nessus provides a plugin with the ID 266222 (Mattermost Server 10.5.x < 10.5.10 / 10.11.0 URL Redirection (MMSA-2025-00511)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 10.5.10 or 10.11.0 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (266222) and EUVD (EUVD-2025-29172). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.1
VulDB Meta Temp Score: 4.1

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

NVD Base Score: 6.1
NVD Vector: 🔒

CNA Base Score: 3.1
CNA Vector (Mattermost): 🔒

CVSSv2info

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

Exploitinginfo

Class: Redirect
CWE: CWE-601
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: 266222
Nessus Name: Mattermost Server 10.5.x < 10.5.10 / 10.11.0 URL Redirection (MMSA-2025-00511)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Mattermost 10.5.10/10.11.0

Timelineinfo

08/15/2025 CVE reserved
09/15/2025 +31 days Advisory disclosed
09/15/2025 +0 days VulDB entry created
10/02/2025 +17 days VulDB entry last update

Sourcesinfo

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

CVE: CVE-2025-9084 (🔒)
GCVE (CVE): GCVE-0-2025-9084
GCVE (VulDB): GCVE-100-323901
EUVD: 🔒

Entryinfo

Created: 09/15/2025 14:51
Updated: 10/02/2025 14:17
Changes: 09/15/2025 14:51 (65), 09/15/2025 16:16 (1), 09/17/2025 01:51 (11), 10/02/2025 14:17 (2)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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