CVE-2026-86540
knowns before 0.30.0 Arbitrary Code Execution via LSP Binary
- State
- Published
- Severity
- 8.5 High
- Published
- Sep 7, 2026
- Updated
- Sep 24, 2026
- Reserved
- Sep 7, 2026
Description
knowns versions before 0.30.0 fail to validate the settings.lsp.languages binary field in project configuration files, allowing attackers to execute arbitrary binaries by crafting a malicious .knowns/config.json file. When a repository with a crafted configuration is opened, the unvalidated binary path is executed twice under the user's account without any verification.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 8.5 High | CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N | VulnCheck |
| 3.1 | 7.8 High | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H | VulnCheck |
Weaknesses
- CWE-78 Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
Affected Products
| Product | Versions |
|---|---|
knownsknowns-dev |
|
References
- GitHub Security Advisory (GHSA-mc52-mwq4-vfx3)vendor-advisory
- Detector.resolve executes the unvalidated binary override (v0.29.1)technical-description
- ProjectSettings.Validate does not inspect the LSP binary field (v0.29.1)technical-description
- knowns fix commit d3989829fb50patch
- knowns v0.30.0 Release Notesrelease-notes
- VulnCheck Advisory: knowns before 0.30.0 Arbitrary Code Execution via LSP Binarythird-party-advisory
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