CVE-2026-28736 | Mattermost Focalboard up to 8.0 authorization

VDB-355102 · CVE-2026-28736 · GCVE-0-2026-28736 MATTERMOST FOCALBOARD UP TO 8.0 AUTHORIZATION HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 4.2 $0-$5k 0.55+ Summaryinfo A vulnerability was found in Mattermost Focalboard up to 8.0. It has been declared as problematic. Affected by this vulnerability is an unknown functionality. Executing a manipulation can lead to authorization. This vulnerability only affects products that are no longer supported by the maintainer. This vulnerability is tracked as CVE-2026-28736. The attack can be launched remotely. No exploit exists. Detailsinfo A vulnerability was found in Mattermost Focalboard up to 8.0. It has been declared as problematic. This vulnerability affects some unknown processing. The manipulation with an unknown input leads to a authorization vulnerability. The CWE definition for the vulnerability is CWE-639. The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data. As an impact it is known to affect confidentiality. CVE summarizes: ** UNSUPPORTED WHEN ASSIGNED ** Focalboard version 8.0 fails to validate file ownership when serving uploaded files. This allows an authenticated attacker who knows a victim's fileID to read the content of the file. NOTE: Focalboard as a standalone product is not maintained and no fix will be issued. The advisory is available at github.com. This vulnerability was named CVE-2026-28736 since 04/03/2026. The exploitation appears to be easy. The attack can be initiated remotely. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 04/03/2026). There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product. Productinfo Type Groupware Software Vendor Mattermost Name Focalboard Version 8.0 License open-source Support end of life CPE 2.3info 🔒 CPE 2.2info 🔒 CVSSv4info VulDB Vector: 🔒 VulDB Reliability: 🔍 CVSSv3info VulDB Meta Base Score: 4.3 VulDB Meta Temp Score: 4.2 VulDB Base Score: 4.3 VulDB Temp Score: 4.2 VulDB Vector: 🔒 VulDB Reliability: 🔍 CNA Base Score: 4.3 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-639 / CWE-285 / CWE-266 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: no mitigation known Status: 🔍 0-Day Time: 🔒 Timelineinfo 04/03/2026 Advisory disclosed 04/03/2026 +0 days CVE reserved 04/03/2026 +0 days VulDB entry created 04/03/2026 +0 days VulDB entry last update Sourcesinfo Advisory: github.com Status: Not defined CVE: CVE-2026-28736 (🔒) GCVE (CVE): GCVE-0-2026-28736 GCVE (VulDB): GCVE-100-355102 Entryinfo Created: 04/03/2026 17:05 Changes: 04/03/2026 17:05 (62) Complete: 🔍 Cache ID: 99:4DA:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸