CVE-2026-88899

Description

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.

References

• https://github.com/knowns-dev/knowns/blob/v0.30.0/internal/server/server.go#L1283-L1296
• 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/security/advisories/GHSA-9h2q-r9fh-f98w
• https://www.vulncheck.com/advisories/knowns-before-0.31.0-external-control-of-agent-working-directory-via-x-opencode-directory-header