# CVE-2026-108940: EricLBuehler Mistral.rs path traversal in calibration_apply

Source: https://junglewise.ai/threats/cve-2026-108940-a-vulnerability-was-found-in-ericlbuehler-mistral-rs-up-to-0-9-3  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-13. Updated: 2026-10-16  
License: CC BY 4.0 with a link back

CVE-2026-108940 · Severity: medium · CVSS 6.5 · Published 2026-10-13

Mistral.rs is a Rust-based inference engine for large language models. An attacker can exploit a path traversal vulnerability in the calibration feature by manipulating a file path parameter, potentially allowing unauthorized file access or modification on the server. The vulnerability can be triggered remotely without authentication.

Technologies: [EricLBuehler Mistral.Rs](https://junglewise.ai/threats/technologies/mistral-rs). Vendors: [EricLBuehler](https://junglewise.ai/threats/vendors/ericlbuehler).

## Quick answers

**Is CVE-2026-108940 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-108940 being exploited in the wild.

**How severe is CVE-2026-108940?** Medium severity, with a CVSS score of 6.5, published 13 October 2026.

**Which products and versions are affected?** EricLBuehler Mistral.Rs up to 0.9.3.

**Is there a fix for CVE-2026-108940?** Yes: fixed in 0.9.4. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-108940 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-108940?** Check whether you run EricLBuehler Mistral.Rs at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 0.9.4

## Technical details

A path traversal flaw exists in the calibration_apply function within mistralrs-server-core/src/handlers.rs, where insufficient input validation on the save_cimatrix parameter allows directory traversal sequences (e.g., "../"). An attacker can remotely send a crafted request with path traversal characters to access or write files outside the intended calibration directory. The fix restricts the parameter to accept only bare filenames, blocking traversal attempts.

## Affected products

- EricLBuehler Mistral.rs up to 0.9.3

## Timeline

- 2026-10-13: disclosed

## References

- [https://github.com/EricLBuehler/mistral.rs/](https://github.com/EricLBuehler/mistral.rs/)
- [https://github.com/EricLBuehler/mistral.rs/commit/8c8105671](https://github.com/EricLBuehler/mistral.rs/commit/8c8105671)

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