Security readout for executives and security teams
Plain-English summary
Mattermost Server versions before 2.2.0 may allow cross-site scripting when configured files open in a browser window. This could let attacker-supplied content execute in a user's browser. The source bundle does not provide severity, CVSS, affected deployment details, or confirmed exploitation.
Executive priority
Prioritize remediation if any legacy Mattermost Server before 2.2.0 remains in use. The issue is old, but exposed collaboration platforms can create business risk through browser-based account or session abuse.
Technical view
CVE-2016-11083 describes an XSS issue in Mattermost Server before 2.2.0 tied to file-opening behavior in browser windows. No CWE, CVSS vector, exploit prerequisites, authentication context, or exact vulnerable file types are included in the provided sources.
Likely exposure
Exposure appears limited to Mattermost Server deployments running versions earlier than 2.2.0. The source bundle does not identify specific editions, hosting models, configurations, or CPEs beyond the CVE description.
Exploitation context
The bundle marks KEV as false and provides no cited evidence of active exploitation or public exploit availability. Treat exploitation status as unconfirmed, not absent.
Researcher notes
Evidence is sparse. The record states XSS caused by opening configured files in a browser window, but does not describe attack path, privileges, payload location, or impact scope. Validation should focus on version exposure and vendor advisory correlation.
Mitigation direction
- Identify any Mattermost Server deployments below version 2.2.0.
- Upgrade away from versions before 2.2.0 using Mattermost guidance.
- Review Mattermost security updates for supported remediation details.
- Restrict exposure of legacy Mattermost instances until upgraded.
- Review file-handling settings if upgrade timing is delayed.
Validation and detection
- Inventory Mattermost Server versions across production and non-production.
- Confirm no running instance reports a version before 2.2.0.
- Check vendor security notes for this CVE or related release guidance.
- Review browser-executed file handling in legacy deployments.
- Search logs for suspicious file access or XSS indicators.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CVE-2016-11083 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://mattermost.com/security-updates/CVE reference · x_refsource_CONFIRM
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.