High severity · published Sep 7, 2026
CVE-2026-86538
knowns before 0.30.0 Path Traversal via templateFile parameter
7.5
CVSS
1%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)1.0% · higher than 62% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
KN
knowns · knowns-dev
before 0.30.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-86538
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-86538
github.com
https://github.com/knowns-dev/knowns/blob/v0.29.1/internal/server/routes/templates.go#L299-L310
github.com
https://github.com/knowns-dev/knowns/commit/09c5a96fd5817b941dc86669278c1a17db10ed4e
github.com
https://github.com/knowns-dev/knowns/releases/tag/v0.30.0
github.com
https://github.com/knowns-dev/knowns/security/advisories/GHSA-fpxv-c555-rhm3
www.vulncheck.com
https://www.vulncheck.com/advisories/knowns-before-0.30.0-path-traversal-via-templatefile-parameter
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