CVE-2026-88899 PUBLISHED

knowns before 0.31.0 External Control of Agent Working Directory via x-opencode-directory Header

Assigner: VulnCheck
Reserved: 10.09.2026 Published: 10.09.2026 Updated: 10.09.2026

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.

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS Score: 9.3

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	High	Confidentiality	None
Attack Complexity	Low	Integrity	High	Integrity	None
Attack Requirements	None	Availability	High	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS Score: 9.8

Attack Vector	Network	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	High
Privileges Required	None	Integrity Impact	High
User Interaction	None	Availability Impact	High

CVSS 3.1

Product Status

Vendor	knowns-dev
Product	knowns
Versions	Default: unaffected affected from 0 to 0.31.0 (excl.) Version 0.31.0 is unaffected

CVE-2026-88899 PUBLISHED

knowns before 0.31.0 External Control of Agent Working Directory via x-opencode-directory Header

Metrics

Product Status

Credits

References

Problem Types