Security readout for executives and security teams
Plain-English summary
CVE-2016-11065 affects Mattermost Server before 3.3.0. The reported issue allowed an attacker to abuse WebSocket functionality to send pop-up messages to users or alter how a post appeared. The bundle does not show data theft, code execution, or service takeover, but it could undermine trust in internal communications.
Executive priority
Prioritize remediation if Mattermost is used for internal operations or incident response communications. The main business risk is message integrity and user trust, with severity constrained by incomplete public evidence.
Technical view
The vulnerability is described as a WebSocket-related flaw in Mattermost Server before 3.3.0. The documented effects are unauthorized pop-up messages and changed post appearance. The source bundle provides no CVSS, CWE, authentication requirement, exploit details, or deeper root-cause information.
Likely exposure
Exposure is likely limited to organizations still running Mattermost Server versions earlier than 3.3.0. The bundle does not identify specific editions, configurations, or deployment patterns beyond that version boundary.
Exploitation context
The CVE is not listed as KEV in the provided bundle, and no cited source states active exploitation. The described abuse is interface manipulation through WebSocket behavior, not confirmed remote code execution or privilege escalation.
Researcher notes
Evidence is sparse. The public description names the WebSocket feature and two UI-level impacts, but omits prerequisites, affected configuration, CVSS, CWE, patch details, and exploit maturity. Avoid assuming broader impact without vendor confirmation.
Mitigation direction
- Identify any Mattermost Server instances older than 3.3.0.
- Upgrade affected Mattermost Server deployments to 3.3.0 or later.
- Review Mattermost security updates for vendor-specific remediation guidance.
- Monitor collaboration channels for suspicious pop-ups or altered post presentation.
Validation and detection
- Inventory Mattermost Server versions across production and non-production environments.
- Confirm no externally reachable instance runs a version before 3.3.0.
- Review security logs for unusual WebSocket activity around affected systems.
- Check vendor advisories for any additional affected-version details.
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-2016-11065 mapping review
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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.