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High severity · published Sep 7, 2026
CVE-2026-86540
knowns before 0.30.0 Arbitrary Code Execution via LSP Binary
7.8
CVSS
0.2%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 11% 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
Affected product
KN
knowns
knowns-dev
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-86540
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-86540
github.com
https://github.com/knowns-dev/knowns/blob/v0.29.1/internal/lsp/detect.go#L128-L157
github.com
https://github.com/knowns-dev/knowns/blob/v0.29.1/internal/models/config.go#L205-L216
github.com
https://github.com/knowns-dev/knowns/commit/d3989829fb5095666d23d005b2f78a082832a396
github.com
https://github.com/knowns-dev/knowns/releases/tag/v0.30.0
github.com
https://github.com/knowns-dev/knowns/security/advisories/GHSA-mc52-mwq4-vfx3
www.vulncheck.com
https://www.vulncheck.com/advisories/knowns-before-0.30.0-arbitrary-code-execution-via-lsp-binary
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