CVE-2026-86538

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.

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