# CVE-2026-50126: Null dereference in adaguc-server

> An attacker can crash the adaguc-server backend by sending a crafted GeoJSON file via an unauthenticated WMS request, causing a denial of service.

- **Severity:** Medium 4.0 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 18 Aug 2026
- **Updated:** 18 Aug 2026
- **Also known as:** GHSA-mwgv-59vv-rp2m

## What is CVE-2026-50126?

CVE-2026-50126 is a medium-severity vulnerability in KNMI adaguc-server, published on 18 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Adaguc-server is an open source geographical information system to visualize, combine, compare and share real-time meteorological, climatological and remote sensing data via OGC standards. Versions prior to 7.2.2 crash with a memory-safety fault when it parses a GeoJSON document whose geometry contains a malformed coordinate. The coordinate parser in `adagucserverEC/CConvertGeoJSON.cpp` indexes `pt.u.array.values[0]` and `pt.u.array.values[1]` and uses `polygon.u.array.length` as a loop bound without first validating the JSON node type or the coordinate length. A coordinate that is an empty array, a one-element array, a scalar, or `null` leads to an out-of-bounds heap read or a NULL pointer dereference. The same unchecked pattern is present in four geometry branches: `Polygon`, `LineString`, `MultiLineString` and `MultiPolygon`. The vulnerable parser runs whenever the server processes a local GeoJSON file, either a configured GeoJSON dataset or a GeoJSON file exposed through the `AutoResource` feature and requested by an unauthenticated WMS request. A crafted GeoJSON file reliably crashes the backend process that handles that request. Version 7.2.2 patches the vulnerability.

Weakness: CWE-476 (NULL Pointer Dereference), CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-50126?


## How do I fix CVE-2026-50126?

No fix has been published for CVE-2026-50126 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-50126 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-50126 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-50126 and fix it if it is affected.

What it is: CVE-2026-50126 is a medium-severity vulnerability in KNMI adaguc-server, published on 18 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-50126 exists.

Affected product: KNMI adaguc-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-2026-50126/ (Markdown: https://insights.sbomify.com/CVE-2026-50126/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-50126
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-50126
- OSV: https://osv.dev/vulnerability/CVE-2026-50126

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-50126/
Summaries are generated and may contain mistakes; the official description above is the record.