CVE-2026-3524 | Mattermost Legal Hold Plugin up to 1.1.4 API authorization

VDB-355520 · CVE-2026-3524 · GCVE-0-2026-3524 MATTERMOST LEGAL HOLD PLUGIN UP TO 1.1.4 API AUTHORIZATION HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 7.4 $0-$5k 1.81+ Summaryinfo A vulnerability was found in Mattermost Legal Hold Plugin up to 1.1.4 and classified as critical. Affected by this vulnerability is an unknown functionality of the component API Handler. Such manipulation leads to authorization. This vulnerability is referenced as CVE-2026-3524. It is possible to launch the attack remotely. No exploit is available. It is suggested to upgrade the affected component. Detailsinfo A vulnerability, which was classified as critical, has been found in Mattermost Legal Hold Plugin up to 1.1.4. Affected by this issue is an unknown code of the component API Handler. The manipulation with an unknown input leads to a authorization vulnerability. Using CWE to declare the problem leads to CWE-862. The product does not perform an authorization check when an actor attempts to access a resource or perform an action. Impacted is confidentiality, integrity, and availability. CVE summarizes: Mattermost Plugin Legal Hold versions <=1.1.4 fail to halt request processing after a failed authorization check in ServeHTTP which allows an authenticated attacker to access, create, download, and delete legal hold data via crafted API requests to the plugin's endpoints. Mattermost Advisory ID: MMSA-2026-00621 The weakness was published by Hassan Mohammed. The advisory is shared for download at mattermost.com. This vulnerability is handled as CVE-2026-3524 since 03/04/2026. The exploitation is known to be easy. The attack may be launched remotely. There are neither technical details nor an exploit publicly available. Upgrading to version 1.1.5 eliminates this vulnerability. Productinfo Type Groupware Software Vendor Mattermost Name Legal Hold Plugin Version 1.1.0 1.1.1 1.1.2 1.1.3 1.1.4 License open-source CPE 2.3info 🔒 🔒 🔒 CPE 2.2info 🔒 🔒 🔒 CVSSv4info VulDB Vector: 🔒 VulDB Reliability: 🔍 CVSSv3info VulDB Meta Base Score: 7.6 VulDB Meta Temp Score: 7.4 VulDB Base Score: 6.3 VulDB Temp Score: 6.0 VulDB Vector: 🔒 VulDB Reliability: 🔍 CNA Base Score: 8.8 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: Authorization CWE: CWE-862 / CWE-863 / CWE-285 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: Legal Hold Plugin 1.1.5 Timelineinfo 03/04/2026 CVE reserved 04/06/2026 +32 days Advisory disclosed 04/06/2026 +0 days VulDB entry created 04/06/2026 +0 days VulDB entry last update Sourcesinfo Advisory: mattermost.com Researcher: Hassan Mohammed Status: Confirmed CVE: CVE-2026-3524 (🔒) GCVE (CVE): GCVE-0-2026-3524 GCVE (VulDB): GCVE-100-355520 Entryinfo Created: 04/06/2026 16:11 Changes: 04/06/2026 16:11 (65) Complete: 🔍 Cache ID: 99:908:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸