# CVE-2026-123356: GROBID: Unauthenticated `/api/modelTraining` Endpoint Allows Unbounded Thread Pool Creation (DoS)


- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 6 Nov 2026
- **Updated:** 9 Nov 2026
- **Also known as:** GHSA-g2r5-4c8r-c84f

## What is CVE-2026-123356?

CVE-2026-123356 is a high-severity vulnerability in grobidOrg grobid, published on 6 Nov 2026. 

### Official description

GROBID is machine learning software for extracting information from scholarly documents. Prior to 0.9.1, the unauthenticated /api/modelTraining endpoint calls GrobidRestProcessTraining.trainModel in GrobidRestProcessTraining.java, where each request creates Executors.newFixedThreadPool(1), submits a training task, and leaves the executor running. Repeated requests permanently retain JVM worker threads and can exhaust process or operating-system thread capacity, degrading or stopping request processing. This issue is fixed in version 0.9.1.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2026-123356?


## How do I fix CVE-2026-123356?

No fix has been published for CVE-2026-123356 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-123356 being exploited?

There is no known exploitation of CVE-2026-123356 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-123356 and fix it if it is affected.

What it is: CVE-2026-123356 is a high-severity vulnerability in grobidOrg grobid, published on 6 Nov 2026. 
Exploitation: There is no known exploitation of CVE-2026-123356 in the wild and no public exploit code.

Affected product: grobidOrg grobid. 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-2026-123356/ (Markdown: https://insights.sbomify.com/CVE-2026-123356/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-123356
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-123356
- OSV: https://osv.dev/vulnerability/CVE-2026-123356

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-123356/
Summaries are generated and may contain mistakes; the official description above is the record.