Security readout for executives and security teams
Plain-English summary
CVE-2026-0543 is a denial-of-service issue in Elastic Kibana’s Email Connector. An authenticated user with sufficient view-level privileges to run connector actions can submit a specially crafted email address value that makes Kibana allocate excessive resources and become unavailable for all users until manually restarted.
Executive priority
Treat as a near-term availability risk for Kibana-dependent operations. Prioritize environments where many users rely on Kibana dashboards, alerting, or investigations, especially if connector actions are broadly available.
Technical view
The issue is improper input validation (CWE-20) in Kibana’s Email Connector. The CVSS 3.1 score is 6.5, with network access, low attack complexity, low privileges, no user interaction, and high availability impact. The provided record lists Kibana 7.0.0, 8.0.0, 9.0.0, and 9.2.0 in affected version data, but range details are incomplete.
Likely exposure
Exposure is most relevant where Kibana is deployed with Email Connector actions available to authenticated users. The attacker needs privileges sufficient to execute connector actions, not administrative control. Internet-facing Kibana increases practical risk, but authentication is required.
Exploitation context
No active exploitation is indicated by the provided sources, and the CVE is not listed as KEV. The impact is availability-only: successful exploitation can make Kibana unavailable to all users until a manual restart is performed.
Researcher notes
Evidence supports authenticated denial of service through Email Connector input validation failure. Version-range and fixed-version details are not fully present in the provided CVE data, so validation should anchor on Elastic’s advisory before making remediation decisions.
Mitigation direction
- Review Elastic ESA-2026-08 and apply the Kibana security update it recommends.
- Restrict connector action execution to trusted roles only.
- Limit external access to Kibana where possible.
- Monitor Kibana resource usage and availability alerts.
- Prepare operational procedures for safe Kibana restart if service becomes unavailable.
Validation and detection
- Inventory Kibana versions across all environments.
- Check whether Email Connector is configured or enabled.
- Review roles allowed to execute connector actions.
- Compare deployed versions against Elastic ESA-2026-08 guidance.
- Confirm monitoring detects Kibana unavailability and abnormal resource allocation.
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.
CWE-20: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-0543 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
- Medium
- CVSS
- 6.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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 vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H2.83.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.5MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Source materials
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.
Improper Input Validation
Improper Input Validation represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.