Vulnerability DatabaseCVE-2026-88899
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CVE-2026-88899
Published:September 10, 2026
Updated:September 22, 2026
knowns versions before 0.31.0 fail to properly validate the x-opencode-directory request header in the /api/opencode proxy endpoint. Remote attackers can supply arbitrary directory paths to execute file operations outside the project root on the host system.
Affected Packages
https://github.com/knowns-dev/knowns.git (GITHUB):
Affected version(s) >=v0.18.0 <v0.31.0
Fix Suggestion:
Update to version v0.31.0
knowns (NPM):
Affected version(s) >=0.18.0 <0.31.0
Fix Suggestion:
Update to version 0.31.0
Related Resources (6)
https://github.com/knowns-dev/knowns/security/advisories/GHSA-9h2q-r9fh-f98w
https://nvd.nist.gov/vuln/detail/CVE-2026-88899
https://www.vulncheck.com/advisories/knowns-before-0.31.0-external-control-of-agent-working-directory-via-x-opencode-directory-header
https://github.com/knowns-dev/knowns/commit/37db0561b37b48b8bd035a417d7f1da6258ae657
https://github.com/knowns-dev/knowns/releases/tag/v0.31.0
https://github.com/knowns-dev/knowns/blob/v0.30.0/internal/server/server.go#L1283-L1296
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CVSS v4
Base Score:
9.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
9.8
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Weakness Type (CWE)
External Control of File Name or Path
CWE-73
EPSS
Base Score:
0.44