CVE-2026-3109 | Mattermost Plugins up to 10.11.11/11.4.x Webhook Request unusual condition

VDB-353696 · CVE-2026-3109 · GCVE-0-2026-3109 MATTERMOST PLUGINS UP TO 10.11.11/11.4.X WEBHOOK REQUEST UNUSUAL CONDITION HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 2.2 $0-$5k 3.62+ Summaryinfo A vulnerability classified as problematic was found in Mattermost Plugins up to 10.11.11/11.4.x. This affects an unknown part of the component Webhook Request Handler. Such manipulation leads to unusual condition. This vulnerability is documented as CVE-2026-3109. The attack can be executed remotely. There is not any exploit available. Upgrading the affected component is advised. Detailsinfo A vulnerability was found in Mattermost Plugins up to 10.11.11/11.4.x and classified as problematic. Affected by this issue is an unknown function of the component Webhook Request Handler. The manipulation with an unknown input leads to a unusual condition vulnerability. Using CWE to declare the problem leads to CWE-754. The product does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the product. Impacted is availability. CVE summarizes: 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 The weakness was released by thecybertantrik. The advisory is shared for download at mattermost.com. This vulnerability is handled as CVE-2026-3109 since 02/24/2026. The exploitation is known to be difficult. The attack may be launched remotely. The exploitation needs additional levels of successful authentication. There are neither technical details nor an exploit publicly available. Upgrading to version 10.11.12 or 11.5.0 eliminates this vulnerability. Productinfo Type Groupware Software Vendor Mattermost Name Plugins Version 10.11.0 10.11.1 10.11.2 10.11.3 10.11.4 10.11.5 10.11.6 10.11.7 10.11.8 10.11.9 10.11.10 10.11.11 11.0 11.1 11.2 11.3 11.4 License open-source CPE 2.3info 🔒 🔒 🔒 CPE 2.2info 🔒 🔒 🔒 CVSSv4info VulDB Vector: 🔒 VulDB Reliability: 🔍 CVSSv3info VulDB Meta Base Score: 2.2 VulDB Meta Temp Score: 2.2 VulDB Base Score: 2.2 VulDB Temp Score: 2.1 VulDB Vector: 🔒 VulDB Reliability: 🔍 CNA Base Score: 2.2 CNA Vector (Mattermost): 🔒 CVSSv2info 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: Unusual condition CWE: CWE-754 CAPEC: 🔒 ATT&CK: 🔒 Physical: No Local: No Remote: Yes Availability: 🔒 Status: Not defined 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: Plugins 10.11.12/11.5.0 Timelineinfo 02/24/2026 CVE reserved 03/26/2026 +30 days Advisory disclosed 03/26/2026 +0 days VulDB entry created 03/26/2026 +0 days VulDB entry last update Sourcesinfo Advisory: mattermost.com Researcher: thecybertantrik Status: Confirmed CVE: CVE-2026-3109 (🔒) GCVE (CVE): GCVE-0-2026-3109 GCVE (VulDB): GCVE-100-353696 Entryinfo Created: 03/26/2026 19:06 Changes: 03/26/2026 19:06 (65) Complete: 🔍 Cache ID: 99:248:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸