Cyber Resilience

CVE-2026-26935

Medium

Published: 26 February 2026

Published
26 February 2026
Modified
02 March 2026
KEV Added
—
Patch
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CVSS Score v3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0010 27.0th percentile
Risk Priority 13 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-26935 is a medium-severity Improper Input Validation (CWE-20) vulnerability in Elastic Kibana. Its CVSS base score is 6.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 27.0th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 SC-5 (Denial-of-service Protection) and SI-10 (Information Input Validation).

Deeper analysis

CVE-2026-26935 is an improper input validation vulnerability (CWE-20) affecting the internal Content Connectors search endpoint in Kibana. Published on 2026-02-26, it enables a denial of service condition through input data manipulation (CAPEC-153). The issue carries a CVSS v3.1 base score of 6.5 (AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).

A remote attacker with low privileges can exploit this vulnerability over the network with low attack complexity and no user interaction. Exploitation leads to a denial of service, significantly impacting availability without affecting confidentiality or integrity.

Elastic Security Advisory ESA-2026-13 addresses this issue, with details available at https://discuss.elastic.co/t/kibana-8-19-12-9-2-6-9-3-1-security-update-esa-2026-13/385249. Practitioners should consult the advisory for affected Kibana versions and recommended patches.

EU & UK References

Vulnerability details

Improper Input Validation (CWE-20) in the internal Content Connectors search endpoint in Kibana can lead Denial of Service via Input Data Manipulation (CAPEC-153)

CWE(s)
CWE-20

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
attack.mitre.org →
Why these techniques?

Improper input validation in Kibana search endpoint directly enables authenticated remote DoS via application exploitation (crash or resource exhaustion).

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

CVEs Like This One

CVE-2026-0528Same product: Elastic Kibana
CVE-2026-26936Same product: Elastic Kibana
CVE-2026-26937Same product: Elastic Kibana
CVE-2026-33458Same product: Elastic Kibana
CVE-2024-43707Same product: Elastic Kibana
CVE-2026-42398Same product: Elastic Kibana
CVE-2026-26938Same product: Elastic Kibana
CVE-2026-33461Same product: Elastic Kibana
CVE-2025-25015Same product: Elastic Kibana
CVE-2026-4498Same product: Elastic Kibana

Affected Assets

elastic
kibana
9.3.0 · 8.4.0 — 8.19.12 · 9.0.0 — 9.2.6

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SI-10 Information Input Validation good match
prevent

Directly requires validation of all inputs to the Content Connectors search endpoint, blocking the malformed data that triggers the DoS condition.

SC-5 Denial-of-service Protection good match
prevent

Mandates technical controls to protect against or limit the effects of denial-of-service attacks launched via manipulated search input.

SI-4 System Monitoring partial match
detect

Enables continuous monitoring of the Kibana endpoint for anomalous input patterns or resource exhaustion indicative of this attack.

References