CVE-2026-3109 - Vulnerability Details - OpenCVE

Mattermost Plugins versions <=11.4 10.11.11.0 fail to validate webhook request timestamps which allows an attacker to corrupt Zoom meeting state in Mattermost via replayed webhook requests. Mattermost Advisory ID: MMSA-2026-00584

No CVSS v4.0

Attack Vector Network

Attack Complexity High

Privileges Required High

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact Low

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Exploitation none

Automatable no

Technical Impact partial

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Mattermost

Mattermost

unaffected

Version	Status	Constraints
`0`	affected	≤ 10.11.11
`11.5.0`	unaffected	—
`10.11.12`	unaffected	—

No data.

No data.

No data.

Subscriptions

No data.

Tracking

Sign in to view the affected projects.

Advisories

No advisories yet.

Fixes

Solution

Update Mattermost Plugins to versions 11.5.0, 10.11.12 or higher.

Workaround

No workaround given by the vendor.

References

Link	Providers
https://mattermost.com/security-updates

History

Thu, 26 Mar 2026 20:15:00 +0000

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Thu, 26 Mar 2026 16:45:00 +0000

Type	Values Removed	Values Added
Description		Mattermost Plugins versions <=11.4 10.11.11.0 fail to validate webhook request timestamps which allows an attacker to corrupt Zoom meeting state in Mattermost via replayed webhook requests. Mattermost Advisory ID: MMSA-2026-00584
Title		Missing timestamp validation in Zoom webhook handler
Weaknesses		CWE-754
References		https://mattermost.com/security-updates
Metrics		cvssV3_1 `{'score': 2.2, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L'}`

MITRE

Status: PUBLISHED

Assigner: Mattermost

Published: 2026-03-26T16:28:07.362Z

Updated: 2026-03-26T19:52:11.107Z

Reserved: 2026-02-24T10:53:41.124Z

Link: CVE-2026-3109

Vulnrichment

Updated: 2026-03-26T19:50:43.961Z

NVD

Status : Received

Published: 2026-03-26T17:16:41.967

Modified: 2026-03-26T17:16:41.967

Link: CVE-2026-3109

Redhat

No data.

OpenCVE Enrichment

No data.

Weaknesses

CWE-754

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-3109", "assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee", "state": "PUBLISHED", "assignerShortName": "Mattermost", "dateReserved": "2026-02-24T10:53:41.124Z", "datePublished": "2026-03-26T16:28:07.362Z", "dateUpdated": "2026-03-26T19:52:11.107Z"}, "containers": {"cna": {"affected": [{"defaultStatus": "unaffected", "product": "Mattermost", "vendor": "Mattermost", "versions": [{"lessThanOrEqual": "10.11.11", "status": "affected", "version": "0", "versionType": "semver"}, {"version": "11.5.0", "status": "unaffected"}, {"version": "10.11.12", "status": "unaffected"}]}], "credits": [{"lang": "en", "type": "finder", "value": "thecybertantrik"}], "descriptions": [{"lang": "en", "value": "Mattermost Plugins versions <=11.4 10.11.11.0 fail to validate webhook request timestamps which allows an attacker to corrupt Zoom meeting state in Mattermost via replayed webhook requests. Mattermost Advisory ID: MMSA-2026-00584"}], "metrics": [{"cvssV3_1": {"attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "HIGH", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "LOW", "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L", "baseSeverity": "LOW", "baseScore": 2.2}, "format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "description": "CWE-754: Improper Check for Unusual or Exceptional Conditions", "cweId": "CWE-754"}]}], "references": [{"url": "https://mattermost.com/security-updates", "name": "MMSA-2026-00584", "tags": ["vendor-advisory"]}], "solutions": [{"value": "Update Mattermost Plugins to versions 11.5.0, 10.11.12 or higher.", "lang": "en"}], "source": {"advisory": "MMSA-2026-00584", "defect": ["https://mattermost.atlassian.net/browse/MM-67233"], "discovery": "EXTERNAL"}, "title": "Missing timestamp validation in Zoom webhook handler", "providerMetadata": {"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee", "shortName": "Mattermost", "dateUpdated": "2026-03-26T16:28:07.362Z"}, "x_generator": {"engine": "cvelib 1.8.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-3109", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-03-26T17:44:18.070716Z"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-03-26T19:52:11.107Z"}}]}}

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-3109", "assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee", "state": "PUBLISHED", "assignerShortName": "Mattermost", "dateReserved": "2026-02-24T10:53:41.124Z", "datePublished": "2026-03-26T16:28:07.362Z", "dateUpdated": "2026-03-26T16:28:07.362Z"}, "containers": {"cna": {"affected": [{"defaultStatus": "unaffected", "product": "Mattermost", "vendor": "Mattermost", "versions": [{"lessThanOrEqual": "10.11.11", "status": "affected", "version": "0", "versionType": "semver"}, {"version": "11.5.0", "status": "unaffected"}, {"version": "10.11.12", "status": "unaffected"}]}], "credits": [{"lang": "en", "type": "finder", "value": "thecybertantrik"}], "descriptions": [{"lang": "en", "value": "Mattermost Plugins versions <=11.4 10.11.11.0 fail to validate webhook request timestamps which allows an attacker to corrupt Zoom meeting state in Mattermost via replayed webhook requests. Mattermost Advisory ID: MMSA-2026-00584"}], "metrics": [{"cvssV3_1": {"attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "HIGH", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "LOW", "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L", "baseSeverity": "LOW", "baseScore": 2.2}, "format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "description": "CWE-754: Improper Check for Unusual or Exceptional Conditions", "cweId": "CWE-754"}]}], "references": [{"url": "https://mattermost.com/security-updates", "name": "MMSA-2026-00584", "tags": ["vendor-advisory"]}], "solutions": [{"value": "Update Mattermost Plugins to versions 11.5.0, 10.11.12 or higher.", "lang": "en"}], "source": {"advisory": "MMSA-2026-00584", "defect": ["https://mattermost.atlassian.net/browse/MM-67233"], "discovery": "EXTERNAL"}, "title": "Missing timestamp validation in Zoom webhook handler", "providerMetadata": {"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee", "shortName": "Mattermost", "dateUpdated": "2026-03-26T16:28:07.362Z"}, "x_generator": {"engine": "cvelib 1.8.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-3109", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-03-26T17:44:18.070716Z"}}}], "providerMetadata": {"shortName": "CISA-ADP", "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "dateUpdated": "2026-03-26T19:50:43.961Z"}, "title": "CISA ADP Vulnrichment"}]}}