9.1Critical
CVE-2026-86542
knowns before 0.30.0 fails to validate import names in the import routes, allowing unauthenticated attackers to write files outside the imports directory. Attackers can supply traversal sequences in the name parameter to escape the imports directory and overwrite arbitrary files writable by the server process.
What this means for your business
- An attacker can use it remotely, over a network, without a login, and without anyone at your company clicking anything.
- FIRST's prediction model gives it a 0.5% chance of attack attempts being seen in the next 30 days, ranking above 39% of all known flaws.
What to do
- 1Ask your IT team or provider whether any of your systems use the affected product.
- 2If you do, follow the vendor's guidance. No patch reference has been published yet.
Not sure if your company is exposed?
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Scoring
- CVSS
- 9.1 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H- CVSS v4
- 8.8
- Weakness
- CWE-22
- Assigned by
- disclosure@vulncheck.com
Dates
- Published
- 2026-09-07
- Last modified
- 2026-09-08
- Sources
- NVD
References
- https://github.com/knowns-dev/knowns/blob/v0.29.1/internal/server/routes/imports.go#L376-L420
- https://github.com/knowns-dev/knowns/blob/v0.29.1/internal/server/routes/imports.go#L519-L551
- https://github.com/knowns-dev/knowns/commit/d3989829fb5095666d23d005b2f78a082832a396
- https://github.com/knowns-dev/knowns/releases/tag/v0.30.0
- https://github.com/knowns-dev/knowns/security/advisories/GHSA-wh3c-v55g-qfg8
- https://www.vulncheck.com/advisories/knowns-before-0.30.0-path-traversal-via-import-name