CVE-2026-88899
knowns before 0.31.0 External Control of Agent Working Directory via x-opencode-directory Header
CVSS Score
9.8
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-73 |
| Vendor | knowns-dev |
| Product | knowns |
| Published | Sep 10, 2026 |
| Last Updated | Sep 11, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Affected Versions
knowns-dev / knowns
0 < 0.31.0
References
github.com: https://github.com/knowns-dev/knowns/security/advisories/GHSA-9h2q-r9fh-f98w github.com: https://github.com/knowns-dev/knowns/blob/v0.30.0/internal/server/server.go#L1283-L1296 github.com: https://github.com/knowns-dev/knowns/commit/37db0561b37b48b8bd035a417d7f1da6258ae657 github.com: https://github.com/knowns-dev/knowns/releases/tag/v0.31.0 vulncheck.com: https://www.vulncheck.com/advisories/knowns-before-0.31.0-external-control-of-agent-working-directory-via-x-opencode-directory-header
Credits
Tong Hoang Gia (uziii2208)