# CVE-2026-17501: ggml-org llama.cpp JSON-Schema-to-GBNF Conversion json-schema-to-grammar.cpp transform recursion

> Remote attackers can cause denial of service via uncontrolled recursion in the JSON-Schema-to-GBNF conversion function of the llama.cpp library.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 27 Jul 2026
- **Updated:** 29 Jul 2026
- **Also known as:** DEBIAN-CVE-2026-17501, GHSA-h334-888w-8prr, UBUNTU-CVE-2026-17501

## What is CVE-2026-17501?

CVE-2026-17501 is a medium-severity denial of service vulnerability in ggml-org llama.cpp, published on 27 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A flaw has been found in ggml-org llama.cpp e15efe0. This vulnerability affects the function transform of the file common/json-schema-to-grammar.cpp of the component JSON-Schema-to-GBNF Conversion. This manipulation causes uncontrolled recursion. The attack may be initiated remotely. The pull request to fix this issue awaits acceptance.

Weakness: CWE-674 (Uncontrolled Recursion), CWE-404 (Improper Resource Shutdown or Release)

## Which versions are affected by CVE-2026-17501?


## How do I fix CVE-2026-17501?

No fix has been published for CVE-2026-17501 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-17501 being exploited?

There is no known exploitation of CVE-2026-17501 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-17501 and fix it if it is affected.

What it is: CVE-2026-17501 is a medium-severity denial of service vulnerability in ggml-org llama.cpp, published on 27 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-17501 in the wild and no public exploit code.

Affected product: ggml-org llama.cpp. 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-2026-17501/ (Markdown: https://insights.sbomify.com/CVE-2026-17501/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-17501
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-17501
- OSV: https://osv.dev/vulnerability/CVE-2026-17501

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-17501/
Summaries are generated and may contain mistakes; the official description above is the record.