# CVE-2026-18581: ggml-org llama.cpp Jinja Minja Template parser.cpp assertion

> Local attackers can trigger a reachable assertion in the Jinja Minja Template Parser, causing a denial of service in llama.cpp.

- **Severity:** Medium 4.8 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 3 Aug 2026
- **Updated:** 3 Aug 2026
- **Also known as:** DEBIAN-CVE-2026-18581, GHSA-3732-9c5p-7h79, UBUNTU-CVE-2026-18581

## What is CVE-2026-18581?

CVE-2026-18581 is a medium-severity denial of service vulnerability in ggml-org llama.cpp, published on 3 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A vulnerability was determined in ggml-org llama.cpp e15efe0. Affected by this issue is some unknown functionality of the file common/jinja/parser.cpp of the component Jinja Minja Template Parser. Executing a manipulation with the input {{9|9|{ can lead to reachable assertion. The attack requires local access. The exploit has been publicly disclosed and may be utilized. The project was informed of the problem early through an issue report but has not responded yet.

Weakness: CWE-617 (Reachable Assertion)

## Which versions are affected by CVE-2026-18581?


## How do I fix CVE-2026-18581?

No fix has been published for CVE-2026-18581 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-18581 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-18581 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-18581 and fix it if it is affected.

What it is: CVE-2026-18581 is a medium-severity denial of service vulnerability in ggml-org llama.cpp, published on 3 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-2026-18581 exists.

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-2026-18581/ (Markdown: https://insights.sbomify.com/CVE-2026-18581/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-18581
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-18581
- OSV: https://osv.dev/vulnerability/CVE-2026-18581

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-18581/
Summaries are generated and may contain mistakes; the official description above is the record.