# CVE-2026-65011: Graylog2 Server Missing Permission Check on Event Definition Duplicate

> Authenticated users with low privileges can clone private event definitions, exposing sensitive detection logic and configuration details.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 22 Jul 2026
- **Updated:** 24 Jul 2026
- **Also known as:** GHSA-p2j9-4mg8-mm73

## What is CVE-2026-65011?

CVE-2026-65011 is a medium-severity missing authorization vulnerability in graylog2-server, published on 22 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Graylog2 Server before commit 46a2eeb contains a missing per-entity permission check in the POST /events/definitions/{definitionId}/duplicate endpoint that allows authenticated users to clone any event definition. Attackers with the low-privilege eventdefinitions:create capability can read private event definitions including detection queries, aggregation thresholds, grouping fields, schedules, and notification bindings by duplicating them.

Weakness: CWE-862 (Missing Authorization)

## Which versions are affected by CVE-2026-65011?


## How do I fix CVE-2026-65011?

No fix has been published for CVE-2026-65011 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-65011 being exploited?

There is no known exploitation of CVE-2026-65011 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-65011 and fix it if it is affected.

What it is: CVE-2026-65011 is a medium-severity missing authorization vulnerability in graylog2-server, published on 22 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-65011 in the wild and no public exploit code.

Affected product: graylog2-server. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-65011/ (Markdown: https://insights.sbomify.com/CVE-2026-65011/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-65011
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-65011
- OSV: https://osv.dev/vulnerability/CVE-2026-65011

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-65011/
Summaries are generated and may contain mistakes; the official description above is the record.