CVE-2026-3114 | Mattermost up to 10.11.11/11.2.3/11.3.1/11.4.0 Zip data amplification

VDB-353682 · CVE-2026-3114 · GCVE-0-2026-3114 MATTERMOST UP TO 10.11.11/11.2.3/11.3.1/11.4.0 ZIP DATA AMPLIFICATION HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 5.3 $0-$5k 1.81+ Summaryinfo A vulnerability classified as problematic was found in Mattermost up to 10.11.11/11.2.3/11.3.1/11.4.0. Affected is an unknown function of the component Zip Handler. The manipulation results in data amplification. This vulnerability is reported as CVE-2026-3114. The attack can be launched remotely. No exploit exists. Upgrading the affected component is advised. Detailsinfo A vulnerability classified as problematic has been found in Mattermost up to 10.11.11/11.2.3/11.3.1/11.4.0. Affected is an unknown function of the component Zip Handler. The manipulation with an unknown input leads to a data amplification vulnerability. CWE is classifying the issue as CWE-409. The product does not handle or incorrectly handles a compressed input with a very high compression ratio that produces a large output. This is going to have an impact on availability. CVE summarizes: Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to validate decompressed archive entry sizes during file extraction which allows authenticated users with file upload permissions to cause a denial of service via crafted zip archives containing highly compressed entries (zip bombs) that exhaust server memory.. Mattermost Advisory ID: MMSA-2026-00598 The weakness was disclosed by winfunc. The advisory is available at mattermost.com. This vulnerability is traded as CVE-2026-3114 since 02/24/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The technical details are unknown and an exploit is not available. This vulnerability is assigned to T1499 by the MITRE ATT&CK project. Upgrading to version 10.11.12, 11.2.4, 11.3.2, 11.4.1 or 11.5.0 eliminates this vulnerability. Productinfo Type Groupware Software Name Mattermost 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 11.2.0 11.2.1 11.2.2 11.2.3 11.3 11.3.0 11.3.1 11.4.0 License open-source CPE 2.3info 🔒 🔒 🔒 CPE 2.2info 🔒 🔒 🔒 CVSSv4info VulDB Vector: 🔒 VulDB Reliability: 🔍 CVSSv3info VulDB Meta Base Score: 5.4 VulDB Meta Temp Score: 5.3 VulDB Base Score: 4.3 VulDB Temp Score: 4.1 VulDB Vector: 🔒 VulDB Reliability: 🔍 CNA Base Score: 6.5 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: Data amplification CWE: CWE-409 / CWE-404 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: Mattermost 10.11.12/11.2.4/11.3.2/11.4.1/11.5.0 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: winfunc Status: Confirmed CVE: CVE-2026-3114 (🔒) GCVE (CVE): GCVE-0-2026-3114 GCVE (VulDB): GCVE-100-353682 Entryinfo Created: 03/26/2026 19:02 Changes: 03/26/2026 19:02 (64) Complete: 🔍 Cache ID: 99:920:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸