# CVE-2026-86538

## Summary

- **CVE ID:** CVE-2026-86538
- **Severity:** HIGH
- **CVSS Score:** 8.7 (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N)
- **CWE:** CWE-22
- **Published:** Sep 7, 2026
- **Last Modified:** Sep 14, 2026

## Description

knowns versions before 0.30.0 contain a path traversal vulnerability in the POST /api/templates/preview endpoint that allows unauthenticated attackers to read arbitrary files. Attackers can supply directory traversal sequences in the templateFile parameter to bypass path restrictions and read sensitive files like credentials and configuration through the JSON response.

## Affected Products

- knowns-dev — knowns (0)
- knowns-dev — knowns (0.30.0)

## References

- [CNA](https://github.com/knowns-dev/knowns/security/advisories/GHSA-fpxv-c555-rhm3)
- [CNA](https://github.com/knowns-dev/knowns/blob/v0.29.1/internal/server/routes/templates.go#L299-L310)
- [CNA](https://github.com/knowns-dev/knowns/commit/09c5a96fd5817b941dc86669278c1a17db10ed4e)
- [CNA](https://github.com/knowns-dev/knowns/releases/tag/v0.30.0)
- [CNA](https://www.vulncheck.com/advisories/knowns-before-0.30.0-path-traversal-via-templatefile-parameter)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.74%
- **EPSS Percentile:** 52.7

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-17._