# CVE-2026-26936: Inefficient Regular Expression Complexity in Kibana Leading to Denial of Service

> Attackers can cause denial of service in Kibana's AI Inference Anonymization Engine via inefficient regular expressions causing exponential blowup.

- **Severity:** Medium 4.9 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 26 Feb 2026
- **Updated:** 26 Feb 2026
- **Also known as:** BIT-elk-2026-26936, BIT-kibana-2026-26936, GHSA-rr4q-h87q-gm3v, MINI-57r2-cj4j-jg9f, MINI-8gwg-3x7j-x6hf, MINI-9qxm-rvgj-86wj, MINI-f5xh-qmvv-55r4, MINI-q773-82v2-8cfx

## What is CVE-2026-26936?

CVE-2026-26936 is a medium-severity denial of service vulnerability in Elastic Kibana, published on 26 Feb 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

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).

Weakness: CWE-1333 (Inefficient Regular Expression Complexity)

## Which versions are affected by CVE-2026-26936?

2 open source packages ship an affected version, including kibana and elk. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `kibana` | Bitnami | From 8.0.0 | 8.19.11, 9.2.5 |
| `elk` | Bitnami | From 8.0.0 | 8.19.11, 9.2.5 |

Products: Elastic Kibana.

## How do I fix CVE-2026-26936?

Upgrade kibana to a fixed version for your release line: 8.19.11 or 9.2.5.

## Is CVE-2026-26936 being exploited?

There is no known exploitation of CVE-2026-26936 in the wild and no public exploit code.

## Other vulnerabilities in Elastic Kibana

- [CVE-2019-7609](https://insights.sbomify.com/CVE-2019-7609/): Kibana Arbitrary Code Execution (critical 9.8, exploited in the wild)
- [CVE-2025-25015](https://insights.sbomify.com/CVE-2025-25015/): Kibana arbitrary code execution via prototype pollution (critical 9.9)
- [CVE-2024-37288](https://insights.sbomify.com/CVE-2024-37288/): Deserialization in Kibana (critical 9.9)
- [CVE-2023-31415](https://insights.sbomify.com/CVE-2023-31415/): Code injection in Kibana (critical 9.9)
- [CVE-2018-17245](https://insights.sbomify.com/CVE-2018-17245/): Information disclosure in Kibana (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-26936 and fix it if it is affected.

What it is: CVE-2026-26936 is a medium-severity denial of service vulnerability in Elastic Kibana, published on 26 Feb 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-26936 in the wild and no public exploit code.

Affected packages and fixed versions:
- kibana (Bitnami): affected from 8.0.0; fixed in 8.19.11, 9.2.5
- elk (Bitnami): affected from 8.0.0; fixed in 8.19.11, 9.2.5

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-26936/ (Markdown: https://insights.sbomify.com/CVE-2026-26936/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-26936
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-26936
- OSV: https://osv.dev/vulnerability/CVE-2026-26936

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-26936/
Summaries are generated and may contain mistakes; the official description above is the record.