Security readout for executives and security teams
Plain-English summary
CVE-2019-20888 is a denial-of-service issue in older Mattermost Server releases. An attacker could trigger excessive memory consumption through an outgoing webhook or slash command integration, potentially disrupting the chat service. Sources do not indicate data theft, privilege escalation, or active exploitation.
Executive priority
Treat this as a service-availability risk for Mattermost-backed collaboration. Prioritize remediation if Mattermost is business-critical, internet-exposed, or heavily integrated with automation workflows.
Technical view
Mattermost Server before 5.7, 5.6.3, 5.5.2, and 4.10.5 is affected. The documented impact is memory-consumption denial of service via outgoing webhook or slash command integration. Public source data does not provide CVSS scoring, CWE mapping, authentication requirements, or exploit detail.
Likely exposure
Exposure is most likely where Mattermost Server runs below the fixed versions and has outgoing webhook or slash command integrations enabled or reachable. The bundle does not identify deployment-specific prerequisites.
Exploitation context
The CVE is not listed as KEV in the provided bundle, and no cited source states active exploitation. Public details are limited to the denial-of-service vector and affected version thresholds.
Researcher notes
Evidence is sparse: no CVSS, CWE, proof-of-concept status, or authentication context is provided. Avoid assuming remote unauthenticated exploitability. Focus validation on version state, integration surface, and operational symptoms.
Mitigation direction
- Upgrade Mattermost Server to 5.7 or a fixed maintenance release listed by Mattermost.
- Review Mattermost security updates for the supported upgrade path.
- Disable or restrict unnecessary outgoing webhook and slash command integrations.
- Monitor Mattermost memory consumption and availability until upgraded.
Validation and detection
- Confirm the deployed Mattermost Server version is at or above the fixed release threshold.
- Inventory enabled outgoing webhook and slash command integrations.
- Check service monitoring for unexplained memory growth or crashes.
- Verify security update tracking includes Mattermost advisories.
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-2019-20888 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.