CVE-2026-26936
Elastic Kibana 8.0.0 – 8.19.11
Raw vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:HSummary
CVE-2026-26936 is a medium-severity Inefficient Regular Expression Complexity (CWE-1333) vulnerability in Elastic Kibana. Its CVSS base score is 4.9 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked at the 25th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
This vulnerability is AI-related — categorised as Other Platforms; in the Data-Related Vulnerabilities risk domain.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-15 (Development Process, Standards, and Tools) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-26936 is an Inefficient Regular Expression Complexity vulnerability (CWE-1333) affecting the AI Inference Anonymization Engine in Kibana. Published on 2026-02-26, it enables a Denial of Service through Regular Expression Exponential Blowup (CAPEC-492), where crafted regex inputs trigger excessive computation. The issue carries a CVSS v3.1 base score of 4.9 (AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H), indicating moderate severity primarily due to high availability impact.
An attacker with high privileges (PR:H) can exploit this over the network (AV:N) with low complexity (AC:L) and no user interaction required. By submitting specially crafted input to the AI Inference Anonymization Engine, the attacker triggers exponential backtracking in regex processing, leading to high CPU consumption or service crashes that deny availability to legitimate users.
Elastic's security advisory ESA-2026-14, detailed at https://discuss.elastic.co/t/kibana-8-19-11-9-2-5-security-update-esa-2026-14/385250, addresses the vulnerability in affected Kibana versions including 8.19.1 and 9.2.5 through security updates that mitigate the regex complexity issue. Practitioners should apply these patches promptly to prevent exploitation.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-8866
Vulnerability Data
Inefficient Regular Expression Complexity (CWE-1333) in the AI Inference Anonymization Engine in Kibana can lead Denial of Service via Regular Expression Exponential Blowup (CAPEC-492).
- CWE(s)
AI Security AnalysisAI
- AI Category
- Other Platforms
- Risk Domain
- Data-Related Vulnerabilities
- OWASP Top 10 for LLMs 2025
- None mapped
- Classification Reason
- Matched keywords: ai
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation can discover inefficient regex patterns via performance or static analysis.
Development standards and tools can require safe regex construction and forbid known exponential patterns.
Denial-of-service protections limit resource exhaustion caused by expensive regex evaluation.
Input validation can constrain data that would otherwise trigger worst-case regex complexity.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing can detect and reject regex patterns with exponential worst-case complexity.
Secure development lifecycle mandates review of algorithmic efficiency, directly addressing ReDoS-prone regex.
Application security requirements can specify input-validation rules that limit regex complexity.
Secure architecture principles encourage avoidance of computationally expensive constructs such as catastrophic backtracking.
Secure coding standards explicitly prohibit or limit the use of inefficient regular expressions.