# CVE-2026-124028: mistral.rs before 0.9.5 Tool Call Injection via mistralrs-core Output Parsers


- **Severity:** Low 2.3 (`CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 6 Nov 2026
- **Updated:** 9 Nov 2026
- **Also known as:** GHSA-34w8-j94f-8c5w, GHSA-g3jq-5q72-jc6f

## What is CVE-2026-124028?

CVE-2026-124028 is a low-severity vulnerability in EricLBuehler mistral.rs, published on 6 Nov 2026. 

### Official description

mistral.rs before 0.9.5 contains a delimiter injection vulnerability in mistralrs-core that allows attackers to inject tool calls by placing delimiter strings in text the model quotes. Attackers controlling documents, web pages or tool outputs can embed tags like </tool_call> to make qwen-xml, gemma4 or reasoning parsers return extra calls to declared tools with attacker-chosen arguments.

Weakness: CWE-140 (Improper Neutralization of Delimiters)

## Which versions are affected by CVE-2026-124028?


## How do I fix CVE-2026-124028?

No fix has been published for CVE-2026-124028 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-124028 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-124028 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-124028 and fix it if it is affected.

What it is: CVE-2026-124028 is a low-severity vulnerability in EricLBuehler mistral.rs, published on 6 Nov 2026. 
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-124028 exists.

Affected product: EricLBuehler mistral.rs. 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-2026-124028/ (Markdown: https://insights.sbomify.com/CVE-2026-124028/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-124028
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-124028
- OSV: https://osv.dev/vulnerability/CVE-2026-124028

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-124028/
Summaries are generated and may contain mistakes; the official description above is the record.